View Filing Data

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2018	Apr. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	GARTNER INC
Entity Central Index Key	0000749251
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)		91,240,213

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 189,979	$ 538,908
Fees receivable, net of allowances of $7,100 and $12,700 respectively	1,134,964	1,176,843
Deferred commissions	207,161	205,260
Prepaid expenses and other current assets	175,204	124,632
Assets held-for-sale	603,354	542,965
Total current assets	2,310,662	2,588,608
Property, equipment and leasehold improvements, net	223,086	221,507
Goodwill	2,956,642	2,987,294
Intangible assets, net	1,247,771	1,292,022
Other assets	176,867	193,742
Total Assets	6,915,028	7,283,173
Current liabilities:
Accounts payable and accrued liabilities	532,538	666,821
Deferred revenues	1,719,637	1,630,198
Current portion of long-term debt	789,724	379,721
Liabilities held-for-sale	143,957	145,845
Total current liabilities	3,185,856	2,822,585
Long-term debt, net of deferred financing fees	2,186,061	2,899,124
Other liabilities	555,540	577,999
Total Liabilities	5,927,457	6,299,708
Stockholders’ Equity
Preferred stock, $.01 par value, 5,000,000 shares authorized; none issued or outstanding	0	0
Common stock, $.0005 par value, 250,000,000 shares authorized; 163,602,067 shares issued for both periods	82	82
Additional paid-in capital	1,788,045	1,761,383
Accumulated other comprehensive income, net	32,225	1,508
Accumulated earnings	1,613,980	1,647,284
Treasury stock, at cost, 72,391,175 and 72,779,205 common shares, respectively	(2,446,761)	(2,426,792)
Total Stockholders’ Equity	987,571	983,465
Total Liabilities and Stockholders’ Equity	$ 6,915,028	$ 7,283,173

Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 7,100	$ 12,700
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0005	$ 0.0005
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	163,602,067	163,602,067
Treasury stock, common shares (in shares)	72,391,175	72,779,205

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Research	$ 763,924	$ 511,306
Events	46,087	35,269
Consulting	82,896	78,594
Talent Assessment & Other	70,658	0
Total revenues	963,565	625,169
Costs and expenses:
Cost of services and product development	357,209	237,609
Selling, general and administrative	487,745	304,244
Depreciation	16,410	10,240
Amortization of intangibles	51,646	6,290
Acquisition and integration charges	59,266	13,272
Total costs and expenses	972,276	571,655
Operating (loss) income	(8,711)	53,514
Interest expense, net	(35,059)	(5,906)
Other income, net	899	889
(Loss) income before income taxes	(42,871)	48,497
(Benefit) provision for income taxes	(23,284)	12,064
Net (loss) income	$ (19,587)	$ 36,433
Net (loss) income per share:
Basic (in dollars per share)	$ (0.22)	$ 0.44
Diluted (in dollars per share)	$ (0.22)	$ 0.43
Weighted average shares outstanding:
Basic (in shares)	91,005	82,835
Diluted (in shares)	91,005	84,095

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (19,587)	$ 36,433
Other comprehensive income, net of tax:
Foreign currency translation adjustments	20,547	4,371
Interest rate swaps – net change in deferred gain or loss	10,114	(2,568)
Pension plans – net change in deferred actuarial loss	56	48
Other comprehensive income, net of tax	30,717	1,851
Comprehensive income	$ 11,130	$ 38,284

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net (loss) income	$ (19,587)	$ 36,433
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	68,056	16,530
Stock-based compensation expense	30,958	22,576
Deferred taxes	(39,175)	(11,998)
Amortization and write-off of deferred financing fees	1,868	468
Changes in assets and liabilities, net of acquisitions:
Fees receivable, net	56,771	(57,919)
Deferred commissions	(512)	3,002
Prepaid expenses and other current assets	(53,851)	(5,315)
Other assets	14,421	(16,730)
Deferred revenues	76,854	92,373
Accounts payable, accrued, and other liabilities	(133,079)	(109,025)
Cash provided by (used in) operating activities	2,724	(29,605)
Investing activities:
Additions to property, equipment and leasehold improvements	(17,679)	(10,700)
Acquisitions - cash paid (net of cash acquired)	0	(111,165)
Other	1,000	0
Cash used in investing activities	(16,679)	(121,865)
Financing activities:
Proceeds from employee stock purchase plan	4,124	3,022
Proceeds from borrowings	0	955,000
Payments for deferred financing fees	0	(18,773)
Payments on borrowings	(304,813)	0
Purchases of treasury stock	(28,394)	(21,978)
Cash (used in) provided by financing activities	(329,083)	917,271
Net (decrease) increase in cash and cash equivalents and restricted cash	(343,038)	765,801
Effects of exchange rates on cash and cash equivalents and restricted cash	3,610	6,007
Cash and cash equivalents and restricted cash, beginning of period	227,630	1,271,162
Cash and cash equivalents and restricted cash, end of period	$ 567,058	$ 499,354

Business and Basis of Presentation

3 Months Ended

Mar. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Business and Basis of Presentation

Business. Gartner, Inc. (NYSE: IT) is the world’s leading research and advisory company and a member of the S&P 500. We equip business leaders with indispensable insights, advice and tools to achieve their mission-critical priorities and build the successful organizations of tomorrow. We believe that we have an unmatched combination of expert-led, practitioner-sourced and data-driven research that steers clients toward the right decisions on the issues that matter most. We're trusted as an objective resource and critical partner by more than 15,000 organizations in more than 100 countries - across all major functions, in every industry and enterprise size. To learn more about how we help decision makers fuel the future of business, visit gartner.com.

Gartner delivers its principal products and services globally through four business segments: Research, Events, Consulting and Talent Assessment & Other. Our revenues by business segment are discussed below under the heading "Revenue Recognition." When used in these notes, the terms “Gartner,” “Company,” “we,” “us,” or “our” refer to Gartner, Inc. and its consolidated subsidiaries.

Basis of presentation. The accompanying interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”), as defined in the Financial Accounting Standards Board ("FASB") Accounting Standards Codification (“ASC”) Topic 270 for interim financial information and with the applicable instructions of the U.S. Securities and Exchange Commission (“SEC”) Rule 10-01 of Regulation S-X on Form 10-Q and should be read in conjunction with the consolidated financial statements and related notes of the Company filed in its Annual Report on Form 10-K for the year ended December 31, 2017. The fiscal year of Gartner is the twelve-month period from January 1 through December 31. In the opinion of management, all normal recurring accruals and adjustments considered necessary for a fair presentation of financial position, results of operations and cash flows at the dates and for the periods presented herein have been included. The results of operations for the three months ended March 31, 2018 may not be indicative of the results of operations for the remainder of 2018 or beyond.

Principles of consolidation. The accompanying interim condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated.

Use of estimates. The preparation of the accompanying interim condensed consolidated financial statements requires management to make estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenues and expenses. Such estimates include the valuation of fees receivable, goodwill, intangible assets, and other long-lived assets, as well as tax accruals and other liabilities. In addition, estimates are used in revenue recognition, income tax expense or benefit, performance-based compensation charges, depreciation and amortization. Management believes its use of estimates in these interim condensed consolidated financial statements to be reasonable.

Management continually evaluates and revises its estimates using historical experience and other factors, including the general economic environment and actions it may take in the future. Management adjusts these estimates when facts and circumstances dictate. However, these estimates may involve significant uncertainties and judgments and cannot be determined with precision. In addition, these estimates are based on management’s best judgment at a point in time. As a result, differences between our estimates and actual results could be material and would be reflected in the Company’s consolidated financial statements in future periods.

Adoption of new accounting standards. The Company adopted the accounting standards described below during the three months ended March 31, 2018:

Stock Compensation Award Modifications — On January 1, 2018, the Company adopted ASU No. 2017-09, "Compensation—Stock Compensation - Scope of Modification Accounting" ("ASU No. 2017-09"). ASU No. 2017-09 provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The adoption of ASU No. 2017-09 had no impact on the Company's consolidated financial statements.

Retirement Benefits Cost Presentation — On January 1, 2018, the Company adopted ASU No. 2017-07, "Compensation—Retirement Benefits" ("ASU No. 2017-07"). ASU No. 2017-07 improves the reporting of net benefit cost in the financial statements, and provides additional guidance on the presentation of net benefit cost in the income statement and clarifies the components eligible for capitalization. The adoption of ASU No. 2017-07 had an immaterial impact on the classification of benefit expense on the Company's Condensed Consolidated Statements of Operations.

Partial Sales of Non-financial Assets — On January 1, 2018, the Company adopted ASU No. 2017-05, "Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Non-financial Assets" ("ASU No. 2017-05"). ASU No. 2017-05 clarifies the scope of the FASB’s recently established guidance on non-financial asset de-recognition as well as the accounting for partial sales of non-financial assets. It conforms the de-recognition guidance on non-financial assets with the model for revenue transactions. The adoption of ASU No. 2017-05 had no impact on the Company's consolidated financial statements.

Definition of a Business — On January 1, 2018, the Company adopted ASU No. 2017-01, "Clarifying the Definition of a Business" ("ASU No. 2017-01"). ASU No. 2017-01 changes the U.S. GAAP definition of a business. Such change can impact the accounting for asset purchases, acquisitions, goodwill impairment and other assessments. The adoption of ASU No. 2017-01 had no impact on the Company's consolidated financial statements.

Presentation of Restricted Cash — On January 1, 2018, the Company adopted ASU No. 2016-18, "Restricted Cash" ("ASU No. 2016-18"). ASU No. 2016-18 requires that amounts generally described as restricted cash and restricted cash equivalents be presented with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts presented on an entity's statement of cash flows. ASU No. 2016-18 must be applied using a retrospective transition method to each comparative period presented in an entity's financial statements.

As a result of the adoption of ASU No. 2016-18, the Company's restricted cash balances are now included in the beginning-of-period and end-of-period total amounts presented on the accompanying Condensed Consolidated Statements of Cash Flows. When compared to the Company's previously issued statement of cash flows for the three months ended March 31, 2017, the adoption of ASU No. 2016-18 resulted in: (i) a reduction of $18.2 million in cash used in investing activities; (ii) an increase of $43.3 million in the end-of-period total cash amount; and (iii) an increase of $25.1 million in the beginning-of-period total cash amount. Below is a table reconciling the beginning-of-period and end-of-period total cash amounts included in the Condensed Consolidated Balance Sheets to the amounts presented in the Condensed Consolidated Cash Flow Statements (in thousands).



	March 31,				December 31,
	2018		2017		2017		2016
Cash and cash equivalents	$	189,979	$	1,227,891	$	538,908	$	474,233
Restricted cash classified in (1), (2):
Prepaid expenses and other current assets	18,143		25,121		15,148		25,121
Other assets	—		18,150		3,002		—
Cash classified as held-for-sale (3)	19,508		—		10,000		—
Cash and cash equivalents and restricted cash per the Condensed Consolidated Statements of Cash Flows	$	227,630	$	1,271,162	$	567,058	$	499,354

(1)

Restricted cash pertains to escrow accounts established in connection with certain of the Company's business acquisitions. Generally, such cash is restricted to use due to provisions contained in the underlying asset purchase agreement. The Company will disburse the restricted cash to the sellers of the businesses upon satisfaction of any contingencies described in such agreements (e.g., potential indemnification claims, etc.).


(2)	Restricted cash is recorded in Prepaid expenses and other current assets and Other assets in the Company's consolidated balance sheets with the short-term or long-term classification dependent on the projected timing of disbursements to the sellers.


(3)	Represents cash classified as a held-for-sale asset for certain businesses that were acquired as part of the CEB acquisition. See Note 2 — Acquisitions and Divestitures for additional information.

Income Taxes — On January 1, 2018, the Company adopted ASU No. 2016-16, "Intra-Entity Transfers of Assets Other Than Inventory" ("ASU No. 2016-16"). ASU No. 2016-16 accelerates the recognition of taxes on certain intra-entity transactions. U.S. GAAP previously required deferral of the income tax implications of an intercompany sale of assets until the assets were sold to a third party or recovered through use. Under ASU No. 2016-16, the seller’s tax effects and the buyer’s deferred taxes on asset transfers are immediately recognized upon the sale.

Pursuant to the transition rules in ASU No. 2016-16, any taxes attributable to pre-2018 intra-entity transfers that were previously deferred should be accelerated and recorded to accumulated earnings on the date of adoption. As a result of this transition rule, certain of the Company's balance sheet income tax accounts pertaining to pre-2018 intra-entity transfers, which aggregated $13.7 million, were reversed against accumulated earnings on January 1, 2018. ASU No. 2016-16 could have a material post-adoption impact on the Company's consolidated financial statements, depending on the nature, size and tax consequences of future intra-entity transfers, if any. However, ASU 2016-16 had no impact on the Company's operating results during the three months ended March 31, 2018.

Statement of Cash Flows — On January 1, 2018, the Company adopted ASU No. 2016-15, "Classification of Certain Cash Receipts and Cash Payments" ("ASU No. 2016-15"). ASU No. 2016-15 sets forth classification requirements for certain cash flow transactions. The adoption of ASU No. 2016-15 had no impact on the Company's consolidated financial statements.

Financial Instruments Recognition and Measurement — On January 1, 2018, the Company adopted ASU No. 2016-01, "Financial Instruments Overall - Recognition and Measurement of Financial Assets and Liabilities" ("ASU No. 2016-01") to address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Among the significant changes required by ASU No. 2016-01 is that equity investments are to be measured at fair value with changes in fair value recognized in net income. The adoption of ASU No. 2016-01 had no impact on the Company's consolidated financial statements.

Revenue Recognition — On January 1, 2018, the Company adopted ASU No. 2014-09, "Revenue from Contracts with Customers" ("ASU No. 2014-09"). The adoption of the standard did not have a material impact on the Company's accounting policies or consolidated financial statements. However, as required by ASU No. 2014-09, the Company's disclosures around revenue recognition have been significantly expanded.

The following sections provide an overview of the Company's revenues by segment along with the required disclosures under the new standard:

Our business and our revenues

Research

Research provides trusted, objective insights and advice on the mission-critical priorities of leaders across all functional areas of an enterprise through research and other reports, briefings, proprietary tools, access to our analysts, peer networking services and membership programs that enable our clients to make better decisions. Gartner's traditional strengths in information technology (“IT”), marketing and supply chain research were enhanced in 2017 with Gartner's acquisition of CEB Inc. ("CEB"), which added CEB's best practice and talent management research insights across a range of business functions, to include human resources, finance, sales and legal.

Research revenues are mainly derived from subscription contracts for research products, representing approximately 90% of the segment’s revenue. The related revenues are deferred and recognized ratably over the applicable contract term (i.e., as we provide the service over the contract period). Fees derived from assisting organizations in selecting the right business software for their needs are recognized at a point in time (i.e., when the lead is provided to the vendor).

The Company enters into subscription contracts for research products that generally are for twelve-month periods or longer. Approximately 65% of our annual and multi-year Research subscription contracts provide for billing of the first annual period upon signing. In subsequent years, multi-year subscription contracts are normally billed prior to the contract’s anniversary date. Our other Research subscription contracts are usually invoiced in advance, commencing with the contract signing, on (i) a quarterly, monthly or other recurring basis or (ii) in accordance with a customized invoicing schedule. Research contracts are generally non-cancelable and non-refundable, except for government contracts that may have cancellation or fiscal funding clauses, which historically have not produced material cancellations. It is our policy to record the amount of a subscription contract that is billable as a fee receivable at the time the contract is signed with a corresponding amount as deferred revenue because the contract represents a legally enforceable claim.

Events

Events provides business professionals across an organization with the opportunity to learn, share and network. From our flagship Chief Information Officer event, Gartner Symposium/ITxpo, to industry-leading conferences focused on specific business roles and topics, to member-driven sessions, our events enable attendees to experience the best of Gartner insight and advice live.

We earn revenues from both the attendees and exhibitors at our events. Attendees are generally invoiced for the full attendance fee upon their completion of an online registration form or their signing of a contract, while exhibitors typically make several individual payments commencing with the signing of a contract. We collect almost all of the invoiced amounts in advance of the related event, resulting in the recording of deferred revenue. We recognize both the attendee and exhibitor revenue as we satisfy our related performance obligations (i.e., when the related symposium, conference, summit or exhibition is held).

The Company defers certain costs directly related to its events and expenses those costs in the period during which the related symposium, conference or exhibition occurs. The Company's policy is to defer only those costs, primarily prepaid site and production services costs, which are incremental and are directly attributable to a specific event. Other costs of organizing and producing our events, primarily Company personnel and non-event specific expenses, are expensed in the period incurred. At the end of each fiscal quarter, the Company assesses, on an event-by-event basis, whether the expected direct costs of producing a scheduled event will exceed the expected revenues. If such costs are expected to exceed revenues, the Company records the expected loss in the period determined.

Consulting

Consulting provides customized solutions to unique client needs through on-site, day-to-day support, as well as proprietary tools for measuring and improving IT performance with a focus on cost, performance, efficiency and quality, and contract optimization services.

Consulting revenues, primarily derived from custom consulting and measurement services, are principally generated from fixed fee or time and materials engagements. Revenues from fixed fee engagements are recognized on a proportional performance basis, while revenues from time and material engagements are recognized as work is delivered and/or services are provided. In both of these circumstances, we satisfy our performance obligations and control of the services are passed to our customers over time (i.e., during the duration of the contract or consulting engagement). On a contract-by-contract basis, we typically use actual labor hours incurred compared to total expected labor hours to measure the Company’s proportional performance in respect of our fixed fee engagements. If our labor and other costs on an individual contract are expected to exceed the total contract value or the contract’s funded ceiling amount, the Company reflects an adjustment to the contract’s overall profitability in the period determined. Revenues related to contract optimization engagements are contingent in nature and are only recognized at a point in time when all of the conditions related to their payment have been satisfied.

Consulting customers are invoiced based on the specific terms and conditions in their underlying contracts. We typically invoice our Consulting customers after we have satisfied some or all of the related performance obligation and the related revenue has been recognized. We record fees receivable for amounts that are billed or billable. We also record contract assets, which represent amounts for which we have recognized revenue but lack the unconditional right to payment as of the balance sheet date due to our required continued performance under the relevant contract, progress billing milestones, or other billing-related restrictions. The Company’s contract assets are discussed below.

Talent Assessment & Other

The Talent Assessment & Other segment helps organizations assess, engage, manage and improve talent. These services are provided through knowledge and skills assessments, training programs, workshops, and survey and questionnaire services.

Talent Assessment & Other segment revenues arising from knowledge and skills assessment services are recognized based on the nature of the underlying contract: (i) ratably over the term of the service period; (ii) upon delivery; or (iii) on a proportional performance basis. Revenues from training programs, workshops, and survey and questionnaire products are primarily recognized upon delivery of the service.

In April 2018, the Company sold its CEB Talent Assessment and CEB Workforce Survey and Analytics businesses, which were reported in the Talent Assessment & Other segment. Note 2 - Acquisitions and Divestitures provides additional information regarding these divestitures.

Overview of ASU No. 2014-09

ASU No. 2014-09 requires a five-step evaluative process that consists of:


(1)	Identifying the contract with the customer;


(2)	Identifying the performance obligations in the contract;


(3)	Determining the transaction price for the contract;


(4)	Allocating the transaction price to the performance obligations in the contract; and


(5)	Recognizing revenue when (or as) performance obligations are satisfied.

ASU No. 2014-09 is intended to clarify the principles for recognizing revenue by removing inconsistencies and weaknesses in existing revenue recognition rules; provide a more robust framework for addressing revenue recognition issues; improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets; and provide more useful information to users of financial statements through improved disclosures.

The Company adopted ASU No. 2014-09 using the modified retrospective method of adoption. Under this method of adoption, the cumulative effect of applying the new standard is recorded at the date of initial application, with no restatement of the comparative prior periods presented. The adoption of ASU No. 2014-09 did not result in a cumulative effect adjustment to the Company's Accumulated earnings in its consolidated financial statements. However, the adoption of the new standard required reclassifications of certain amounts presented in the Company’s consolidated balance sheet. As of January 1, 2018, these items were (i) the reclassification of certain fees receivable that met the definition of a contract asset, aggregating $26.7 million, from Fees receivable, net to Prepaid expenses and other current assets; and (ii) the reclassification of a refund liability, aggregating $6.2 million, from the allowance for fees receivable to Accounts payable and accrued liabilities.

Related to our adoption of ASU No. 2014-09, we elected to (i) apply the provisions of this new accounting guidance only to contracts that were not completed at the date of initial application and (ii) utilize a practical expedient whereby we reflected the aggregate effect of all contract modifications that occurred prior to January 1, 2018 (rather than retrospectively restating the affected contracts) when identifying our satisfied and unsatisfied performance obligations, determining the transaction prices with our customers, and allocating such transaction prices to our satisfied and unsatisfied performance obligations. These two elections had no financial impact.

Prior to January 1, 2018, the Company recognized revenue in accordance with then-existing U.S. GAAP and SEC Staff Accounting Bulletin No. 104, "Revenue Recognition" (“prior GAAP”). Under both ASU No. 2014-09 and prior GAAP, revenue can only be recognized when all of the required criteria are met. Although there were some minor changes to the Company’s revenue recognition policies and procedures effective January 1, 2018 with the adoption of ASU No. 2014-09, there were no material differences between the timing and amount of revenues recognized under ASU No. 2014-09 and prior GAAP. The accompanying Condensed Consolidated Statements of Operations present revenues net of any sales or value-added taxes that we collect from customers and remit to government authorities.

ASU No. 2014-09 requires that we assess at inception all of the promises in a customer contract to determine if a promise is a separate performance obligation. To identify our performance obligations, we consider all of the services promised in a customer contract, regardless of whether they are explicitly stated or are implied by customary business practices. If we conclude that a service is separately identifiable and distinct from the other offerings in a contract, we account for such a promise as a separate performance obligation.

If a customer contract has more than one performance obligation, then the total contract consideration is allocated among the separate deliverables based on their stand-alone selling prices, which are determined based on the prices at which the Company discretely sells the stand-alone services. If a contract includes a discount or other pricing concession, the transaction price is allocated among the performance obligations on a proportionate basis using the relative stand-alone selling prices of the individual deliverables being transferred to the customer, unless the discount or other pricing concession can be ascribed to specifically identifiable performance obligations.

The contracts with our customers delineate the final terms and conditions of the underlying arrangement, including product descriptions, subscription periods, deliverables, quantity and price of each service purchased. Since the transaction price of almost all of our customer contracts is typically agreed upon upfront and generally does not fluctuate during the duration of the contract, variable consideration is insignificant. The Company may engage in certain financing transactions with customers but these arrangements have been limited in number and not material.

Required Disclosures under ASU No. 2014-09

ASU No. 2014-09 requires significantly expanded disclosures around the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. These additional disclosures are provided below:

Disaggregated Revenues

We believe that disaggregating the Company’s revenues by primary geographic location and the timing of when revenue is recognized achieves the disclosure objectives in ASU No. 2014-09. Our disaggregated revenue information by reportable segment is presented for the periods indicated in the tables below (in thousands).

Three Months Ended March 31, 2018



	Research		Events		Consulting		Talent Assessment & Other		Total
Primary Geographic Markets: (1)
United States and Canada	$	489,713	$	24,069	$	45,129	$	34,594	$	593,505
Europe, Middle East and Africa	184,547		16,891		29,938		28,290		259,666
Other International	89,664		5,127		7,829		7,774		110,394
Total revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565

Three Months Ended March 31, 2017



	Research		Events		Consulting		Talent Assessment & Other		Total
Primary Geographic Markets: (1)
United States and Canada	$	327,492	$	17,663	$	47,832	$	—	$	392,987
Europe, Middle East and Africa	115,802		14,095		23,823		—		153,720
Other International	68,012		3,511		6,939		—		78,462
Total revenues	$	511,306	$	35,269	$	78,594	$	—	$	625,169


(1)	Revenues are reported based on where the sale is fulfilled.

Three Months Ended March 31, 2018



	Research		Events		Consulting		Talent Assessment & Other		Total
Timing of Revenue Recognition:
Transferred over time (1)	$	701,096	$	—	$	74,010	$	58,946	$	834,052
Transferred at a point in time (2)	62,828		46,087		8,886		11,712		129,513
Total revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565

Three Months Ended March 31, 2017



	Research		Events		Consulting		Talent Assessment & Other		Total
Timing of Revenue Recognition:
Transferred over time (1)	$	466,706	$	—	$	64,994	$	—	$	531,700
Transferred at a point in time (2)	44,600		35,269		13,600		—		93,469
Total revenues	$	511,306	$	35,269	$	78,594	$	—	$	625,169

(1)

These Research revenues were recognized in connection with performance obligations that were satisfied over time using a time-elapsed output method to measure progress. The corresponding Consulting revenues were recognized over time using labor hours as an input measurement basis. Talent Assessment & Other revenues in this category were recognized using either a time-elapsed output method, performance-based milestone approach or labor hours, depending on the nature of the underlying customer contract.


(2)	The revenues in this category were recognized in connection with performance obligations that were satisfied at the point in time the contractual deliverables were provided to the customer.

Determining a measure of progress for performance obligations that are satisfied over time and when control transfers for performance obligations that are satisfied at a point in time requires us to make judgments that affect the timing of when revenue is recognized. A key factor in this determination is when the customer is able to direct the use of, and can obtain substantially all of the benefits from, the deliverable.

For performance obligations recognized in accordance with a time-elapsed output method, the Company’s efforts are expended consistently throughout the contractual period and the Company transfers control evenly by providing stand-ready services. For performance obligations satisfied under our Consulting fixed fee and time and materials engagements, we believe that labor hours are the best measure of depicting the Company’s progress because labor output corresponds directly to the value of the Company’s performance to date as control is transferred. In our Talent Assessment & Other segment, we select a method to assess the completion of our performance obligations that best aligns with the specific characteristics of the individual customer contract. We believe that these methods to measure progress provide a reasonable and supportable determination as to when we transfer control over these services to our customers.

For customer contracts that are greater than one year in duration, the aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2018 was approximately $2.1 billion. The Company expects to recognize $1,060.6 million, $856.7 million and $209.8 million of this revenue (most of which pertains to Research) during the remainder of 2018, the year ending December 31, 2019 and thereafter, respectively. The Company applies the practical expedient allowed in ASU No. 2014-09 and, accordingly, it does not disclose such performance obligation information for customer contracts that have original durations of one year or less.

Customer Contract Assets and Liabilities

The timing of the recognition of revenues, the amount and timing of our billings and cash collections, as well as upfront customer payments, result in the recording of both assets and liabilities on our Condensed Consolidated Balance Sheets.

The payment terms and conditions in our customer contracts vary. In some cases, customers prepay and, in other cases, after we conduct a credit evaluation, payment may be due in arrears. Because the timing of the delivery of our services typically differs from the timing of customer payments, the Company recognizes either a contract asset (we perform either fully or partially under the contract but a contingency remains) or a contract liability (upfront customer payments precede our performance, resulting in deferred revenue). Amounts recorded as contract assets are reclassified to fees receivable when all of the outstanding conditions have been resolved and our right to payment becomes unconditional. Contracts with payments due in arrears are also recognized as fees receivable. As our contractual performance obligations are satisfied over time or at a point in time, the Company correspondingly relieves its contract liabilities and records the associated revenue.

The table below provides information regarding certain of the Company’s balance sheet accounts that pertain to its contracts with customers, to exclude our held-for-sale businesses (in thousands):



	March 31,		December 31,
	2018		2017
Assets:
Fees receivable, gross (1)	$	1,142,064	$	1,162,871

Contract assets (2)	$	27,593	$	26,672

Contract liabilities:
Deferred revenues (current liability) (3)	$	1,719,637	$	1,630,198
Non-current deferred revenues (3)	16,139		16,205
Total contract liabilities	$	1,735,776	$	1,646,403


(1)	Fees receivable represent the unconditional right of payment from our customers and includes both billed and unbilled amounts.

(2)

Contract assets represent recognized revenue for which we do not have an unconditional right to payment as of the balance sheet date because the project may be subject to a progress milestone or some other billing restriction. In the accompanying Condensed Consolidated Balance Sheets, contract assets are recorded in Prepaid expenses and other current assets as of March 31, 2018 and Fees receivable, net as of December 31, 2017.


(3)	Deferred revenues represent amounts (i) for which the Company has received an upfront customer payment or (ii) that pertain to recognized fees receivable. Both situations occur before the completion of our performance obligation(s).

During the three months ended March 31, 2018, the Company recognized $605.5 million of revenue that was attributable to deferred revenues that were recorded at December 31, 2017. Such amount primarily consisted of (i) Research and Talent Assessment & Other revenue that was recognized ratably as control of the goods or services passed to the customer and (ii) Events revenue pertaining to symposia, conferences, summits or exhibitions that occurred during the calendar quarter. During the three months ended March 31, 2018, the Company recorded no material impairments related to its contract assets. The Company does not in the normal course of business recognize revenues from performance obligations satisfied in prior periods.

Allowance for Losses and Revenue Reserves

As of December 31, 2017, the Company maintained an allowance for losses that included a bad debt allowance and a revenue reserve. Provisions to the Company’s allowance for losses were charged against earnings as either a reduction in revenues or an increase in expense.

Effective with the adoption of ASU No. 2014-09 on January 1, 2018, the allowance for losses, which is classified as an offset to the gross amount of fees receivable, and the related charge against earnings (i.e., bad debt expense) is now comprised solely of estimated uncollectible fees receivable due to credit and other associated risks. The revenue reserve previously reported as part of the allowance for losses has been reclassified and is now reported as a liability in accordance with ASU No. 2014-09. The revenue reserve is maintained for amounts deemed to be uncollectible for reasons other than bad debt. The amount of the revenue reserve is based on past experience and current estimates. As of March 31, 2018, the revenue reserve balance was $6.9 million and adjustments to the account during the three months ended March 31, 2018 were not significant.

The determination of the allowance for losses is based on historical loss experience, an assessment of current economic conditions, the aging of outstanding receivables, the financial health of specific clients and probable losses. This evaluation is inherently judgmental and requires the use of estimates. The allowance for losses is periodically re-evaluated and adjusted as more information about the ultimate collectability of fees receivable becomes available. Circumstances that could cause the allowance for losses to increase include changes in our clients’ liquidity and credit quality, other factors negatively impacting our clients’ ability to pay their obligations as they come due, and the effectiveness of our collection efforts.

Costs of obtaining and fulfilling a customer contract

Upon the signing of a customer contract, the Company capitalizes the related commission as a recoverable direct incremental cost of obtaining the underlying contract and records a corresponding commission payable. No other amounts are capitalized as a cost of obtaining or fulfilling a customer contract because no expenditures have been identified that meet the requisite capitalization criteria. For Research, Consulting and Talent Assessment & Other, we generally use the straight-line method of amortization for deferred commissions over a period that is based on the projected recoverability for such costs, using factors such as the underlying contract period, the timing of when the corresponding revenues will be earned, and the anticipated term of the engagement. For Events, deferred commissions are expensed during the period when the related event occurs.

Under all circumstances, deferred commissions are amortized over a period that does not exceed one year. During the three months ended March 31, 2018 and 2017, such amortization expense was $75.9 million and $50.2 million, respectively, and was included in Selling, general and administrative expense in the accompanying Condensed Consolidated Statements of Operations. The Company recorded no material impairments of its deferred commissions during either the three months ended March 31, 2018 or 2017.

Accounting standards issued but not yet adopted. The FASB has issued accounting standards that have not yet become effective and may impact the Company’s consolidated financial statements or related disclosures in future periods. These standards and their potential impact are discussed below:

Accounting standards effective in 2019

Certain Tax Effects Stranded In Accumulated Other Comprehensive Income — In February 2018, the FASB issued ASU No. 2018-02, "Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" ("ASU No. 2018-02"). ASU No. 2018-02 provides an entity with the option to reclassify to retained earnings the tax effects from items that have been stranded in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act of 2017 (the “Act”). Upon adoption, ASU No. 2018-02 requires an entity to make new disclosures, including whether or not the entity elected to reclassify the tax effects related to the Act and the entity’s accounting policy for releasing the income tax effects from accumulated other comprehensive income for all other items (i.e., those not pertaining to the Act). Entities may adopt ASU No. 2018-02 using one of two transition methods: (i) retrospective to each period wherein the income tax effects of the Act related to items remaining in accumulated other comprehensive income are recognized or (ii) at the beginning of the period of adoption. ASU No. 2018-02 is effective for Gartner on January 1, 2019; however, early adoption is permitted. We are currently evaluating the potential impact of ASU No. 2018-02 on the Company's consolidated financial statements but no material impact is expected at adoption.

Targeted Improvements to Accounting for Hedging Activities - In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging ("ASU No. 2017-12"). ASU No. 2017-12 is intended to improve the financial reporting of hedging relationships to better portray economic results of an entity’s risk management activities in its financial statements. In addition to that main objective, the standard makes certain targeted improvements to simplify the application of the hedge accounting guidance in current U.S. GAAP. ASU No. 2017-12 is effective for Gartner on January 1, 2019. We are currently evaluating the impact of ASU No. 2017-12 on the Company's consolidated financial statements.

Distinguishing Liabilities from Equity — In July 2017, the FASB issued ASU No. 2017-11, "Earnings Per Share, Distinguishing Liabilities from Equity, and Derivatives and Hedging" ("ASU No. 2017-11"). ASU No. 2017-11 is intended to simplify the accounting for financial instruments with characteristics of liabilities and equity. Among the issues addressed are: (i) determining whether an instrument (or embedded feature) is indexed to an entity’s own stock; (ii) distinguishing liabilities from equity for mandatorily redeemable financial instruments of certain nonpublic entities; and (iii) identifying mandatorily redeemable non-controlling interests. ASU No. 2017-11 is effective for Gartner on January 1, 2019. We are currently evaluating the potential impact of ASU No. 2017-11 on the Company's consolidated financial statements.

Leases — In February 2016, the FASB issued ASU No. 2016-02, "Leases" ("ASU No. 2016-02"), which will require significant changes in the accounting and disclosure for lease arrangements. Under current U.S. GAAP, lease arrangements that meet certain criteria are considered operating leases and are not recorded on an entity's balance sheet. Because all of our existing lease arrangements are accounted for as operating leases, they are not recorded on the Company's balance sheet. ASU No. 2016-02 will significantly change the accounting for leases because a right-of-use ("ROU") model will be used wherein a lessee must record an ROU asset and a lease liability on its balance sheet for leases with initial terms longer than 12 months. Under ASU No. 2016-02, leases will be classified as either finance or operating arrangements, with such classification affecting the pattern of expense recognition in an entity's income statement. ASU No. 2016-02 also requires expanded disclosures about leasing arrangements. ASU No. 2016-02 will be effective for Gartner on January 1, 2019. We are currently evaluating the potential impact of ASU No. 2016-02 on our consolidated financial statements.

Accounting standards effective in 2020

Goodwill Impairment — In January 2017, the FASB issued ASU No. 2017-04, "Intangibles—Goodwill and Other - Simplifying the Test for Goodwill Impairment" ("ASU No. 2017-04"). ASU No. 2017-04 simplifies the determination of the amount of goodwill to be potentially charged off by eliminating Step 2 of the goodwill impairment test under current U.S. GAAP. ASU No. 2017-04 is effective for Gartner on January 1, 2020. The adoption of ASU No. 2017-04 is currently not expected to have a material impact on the Company's consolidated financial statements.

Financial Instrument Credit Losses — In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments—Credit Losses" ("ASU No. 2016-13"). ASU No. 2016-13 amends the current financial instrument impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables. ASU No. 2016-13 is effective for Gartner on January 1, 2020, with early adoption permitted. We are currently evaluating the potential impact of ASU No. 2016-13 on our consolidated financial statements.

The FASB continues to work on a number of other significant accounting standards which, if issued, could materially impact the Company's accounting policies and disclosures in future periods. As these standards have not yet been issued, the effective dates and potential impact are unknown.

Acquisitions and Divestitures

3 Months Ended

Mar. 31, 2018

Business Combinations [Abstract]

Acquisitions and Divestitures

Acquisitions

The Company accounts for business acquisitions in accordance with the acquisition method of accounting as prescribed by FASB ASC Topic 805, Business Combinations. The acquisition method of accounting requires the Company to record the net assets and liabilities acquired based on their estimated fair values as of the acquisition date, with any excess of the consideration transferred over the estimated fair value of the net assets acquired, including identifiable intangible assets, to be recorded to goodwill. Under the acquisition method, the operating results of acquired companies are included in the Company's consolidated financial statements beginning on the date of acquisition. The Company did not have any business acquisitions in the first quarter of 2018. In the first quarter of 2017, the Company acquired L2, Inc. ("L2"), a subscription-based research business that benchmarks the digital performance of brands. During the three months ended March 31, 2018, the Company finalized its acquisition accounting for L2 and CEB Inc. ("CEB"), which was acquired on April 5, 2017. There were no material measurement period adjustments recorded during the 2018 quarterly period.

The Company recognized $59.3 million of acquisition and integration charges in 2018 compared to $13.3 million in 2017. The additional charges during 2018 consisted of higher professional fees, severance, stock-based compensation charges, and accruals for exit costs for certain office space that the Company does not intend to occupy in Arlington, Virginia that were related to our acquisition of CEB. The following table presents a summary of the activity related to our accrual for exit costs at all of our facilities for the quarter ended March 31, 2018 (in thousands):



Liability balance at December 31, 2017	$	12,961
Charges and adjustments, net	44,230
Payments	(4,734		)
Liability balance at March 31, 2018 (1)	$	52,457


(1)	In total, we estimate that we will make net cash payments of approximately $61.2 million for exit costs in connection with the activities described herein. Through March 31, 2018, in the aggregate, we have expensed $57.3 million and paid $4.9 million related to such activities.

Divestitures

CEB Talent Assessment business

On April 3, 2018, the Company sold its CEB Talent Assessment business in all cash transaction for a purchase price of $400.0 million. The purchase price is subject to customary adjustments and other deal-related expenses. The CEB Talent Assessment business was acquired by Gartner as part of the CEB acquisition in April 2017 and was a significant portion of the Company's Talent Assessment & Other segment. During the first quarter of 2018, the CEB Talent Assessment business contributed approximately $47.0 million of revenue and recognized pre-tax income of approximately $2.1 million.

CEB Workforce Survey & Analytics business

On April 30, 2018, the Company sold its CEB Workforce Survey and Analytics ("WS&A") business in an all cash transaction for a purchase price of $29.0 million. The purchase price is subject to customary adjustments and other deal-related expenses. The WS&A business was also acquired by Gartner as part of the CEB acquisition in April 2017 and was reported with the Talent Assessment & Other segment.

The Company has classified the related assets and liabilities of these businesses as held-for-sale in its Consolidated Balance Sheets.

The principal components of the held-for-sale assets and liabilities for these businesses are summarized in the table below (in thousands):



	March 31, 2018 (1)		December 31, 2017 (1)
Cash and cash equivalents	$	19,508	$	10,000
Fees receivable, net	49,191		50,928
Goodwill	246,661		212,994
Intangible assets, net	264,145		250,472
Other assets (2)	23,849		18,571
Total assets held-for-sale	$	603,354	$	542,965

Accounts payable and accrued liabilities	$	26,467	$	32,388
Deferred revenues	65,846		61,450
Other liabilities	51,644		52,007
Total liabilities held-for-sale	$	143,957	$	145,845

(1) March 31, 2018 includes both the CEB Talent Assessment business and the WS&A business. December 31, 2017 includes the CEB Talent Assessment business only.

(2) Other assets includes property, equipment and leasehold improvements, net.

Computation of Net (Loss) Income per Share

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Computation of Net (Loss) Income per Share

Basic earnings per share (“EPS”) is computed by dividing net (loss) income by the weighted average number of shares of Common Stock outstanding for the period. Diluted EPS reflects the potential dilution of securities that could share in earnings. When the impact of common share equivalents is anti-dilutive, they are excluded from the calculation.

The following table sets forth the calculation of basic and diluted (loss) income per share (in thousands, except per share data):



	Three Months Ended
	March 31,
	2018			2017
Numerator:
Net (loss) income used for calculating basic and diluted (loss) income per common share	$	(19,587	)	$	36,433

Denominator:
Weighted average common shares used in the calculation of basic (loss) income per share	91,005			82,835
Common stock equivalents associated with stock-based compensation plans (1), (2)	—			1,260
Shares used in the calculation of diluted (loss) income per share	91,005			84,095

Basic (loss) income per share	$	(0.22	)	$	0.44
Diluted (loss) income per share	$	(0.22	)	$	0.43


(1)	For the three months ended March 31, 2017, certain common stock equivalents were not included in the computation of diluted income per share because the effect would have been anti-dilutive. These common share equivalents totaled less than 0.4 million for the 2017 period presented.


(2)	For the three months ended March 31, 2018, approximately 1.3 million common stock equivalents were completely excluded from the calculation of diluted (loss) per share because they were anti-dilutive.

Stock-Based Compensation

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

The Company grants stock-based compensation awards as an incentive for employees and directors to contribute to the Company’s long-term success. The Company currently awards stock-settled stock appreciation rights, service-based and performance-based restricted stock units, and common stock equivalents. As of March 31, 2018, the Company had 4.9 million shares of its common stock, par value $.0005 per share, (the “Common Stock”) available for stock-based compensation awards under its 2014 Long-Term Incentive Plan.

The Company accounts for stock-based compensation awards in accordance with FASB ASC Topics 505 and 718 and SEC Staff Accounting Bulletins No. 107 and No. 110. Stock-based compensation expense is based on the fair value of the award on the date of grant. The Company recognizes stock-based compensation expense over the period that the related service is performed, which is generally the same as the vesting period of the underlying award. Currently, the Company issues treasury shares upon the exercise, release or settlement of stock-based compensation awards.

Determining the appropriate fair value model and calculating the fair value of stock-based compensation awards requires the use of certain subjective assumptions, including the expected life of a stock-based compensation award and Common Stock price volatility. In addition, determining the appropriate periodic stock-based compensation expense requires management to estimate the likelihood of the achievement of certain performance targets. The assumptions used in calculating the fair values of stock-based compensation awards and the related periodic expense represent management’s best estimates, which involve inherent uncertainties and the application of judgment. As a result, if circumstances change and the Company deems it necessary in the future to modify the assumptions it made or to use different assumptions, or if the quantity and nature of the Company’s stock-based compensation awards changes, then the amount of expense may need to be adjusted and future stock-based compensation expense could be materially different from what has been recorded in the current period.

Stock-Based Compensation Expense

The Company recognized the following stock-based compensation expense by award type and expense category line item during the periods indicated (in millions):



	Three Months Ended
	March 31,
Award type	2018		2017
Stock appreciation rights	$	3.5	$	2.8
Restricted stock units	27.2		19.6
Common stock equivalents	0.2		0.2
Total (1)	$	30.9	$	22.6



	Three Months Ended
	March 31,
Expense category line item	2018		2017
Cost of services and product development	$	11.4	$	9.3
Selling, general and administrative	18.2		13.3
Acquisition and integration charges (2)	1.3		—
Total (1)	$	30.9	$	22.6

(1) Includes charges of $17.8 million and $14.5 million during the three months ended March 31, 2018 and 2017, respectively, for awards to retirement-eligible employees. Those awards vest on an accelerated basis.

(2) These charges are primarily the result of the acceleration of the vesting of certain restricted stock units related to the CEB acquisition.

As of March 31, 2018, the Company had $125.8 million of total unrecognized stock-based compensation cost, which is expected to be expensed over the remaining weighted average service period of approximately 2.9 years.

Stock-Based Compensation Awards

The disclosures presented below provide information regarding the Company’s stock-based compensation awards, all of which have been classified as equity awards in accordance with FASB ASC Topic 505.

Stock Appreciation Rights

Stock-settled stock appreciation rights ("SARs") permit the holder to participate in the appreciation of the value of the Common Stock. After the applicable vesting criteria have been satisfied, SARs are settled in shares of Common Stock upon exercise by the employee. SARs vest ratably over a four-year service period and expire seven years from the date of grant. The fair value of a SARs award is recognized as compensation expense on a straight-line basis over four years. SARs have only been awarded to the Company’s executive officers.

When SARs are exercised, the number of shares of Common Stock issued is calculated as follows: (1) the total proceeds from the exercise of the SARs award (calculated as the closing price of the Common Stock as reported on the New York Stock Exchange on the date of exercise less the exercise price of the SARs award, multiplied by the number of SARs exercised) is divided by (2) the closing price of the Common Stock on the date of exercise. The Company withholds a portion of the shares of the Common Stock issued upon exercise to satisfy statutory tax withholding requirements. SARs recipients do not have any stockholder rights until the shares of Common Stock are issued in respect of the award, which is subject to the prior satisfaction of the vesting and other criteria relating to such grants.

The following table summarizes changes in SARs outstanding during the three months ended March 31, 2018:



	Stock Appreciation Rights ("SARs") (in millions)	Per Share Weighted Average Exercise Price		Per Share Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (Years)
Outstanding at December 31, 2017	1.2	$	76.73	$	17.35	4.28
Granted	0.3	114.26		25.63		6.86
Outstanding at March 31, 2018 (1) (2)	1.5	85.06		19.15		4.70
Vested and exercisable at March 31, 2018 (2)	0.8	$	70.96	$	16.39	3.56

(1) As of March 31, 2018, 0.7 million of the total SARs outstanding were unvested. The Company expects that substantially all of those unvested awards will vest in future periods.

(2) As of March 31, 2018, the total SARs outstanding had an intrinsic value of $47.6 million. On such date, SARs vested and exercisable had an intrinsic value of $35.1 million.

The fair value of a SARs award is determined on the date of grant using the Black-Scholes-Merton valuation model with the following weighted average assumptions:



	Three Months Ended
	March 31,
	2018		2017
Expected dividend yield (1)	—	%	—	%
Expected stock price volatility (2)	21	%	22	%
Risk-free interest rate (3)	2.5	%	1.8	%
Expected life in years (4)	4.5		4.5


(1)	The expected dividend yield assumption was based on both the Company's historical and anticipated dividend payouts. Historically, the Company has not paid cash dividends on its Common Stock.


(2)	The determination of expected stock price volatility was based on both historical Common Stock prices and implied volatility from publicly traded options in the Common Stock.


(3)	The risk-free interest rate was based on the yield of a U.S. Treasury security with a maturity similar to the expected life of the award.


(4)	The expected life represents the Company’s estimate of the weighted average period of time the SARs are expected to be outstanding (that is, the period between the service inception date and the expected exercise date).

Restricted Stock Units

Restricted stock units ("RSUs") give the awardee the right to receive shares of Common Stock when the vesting conditions are met and certain restrictions lapse. Each RSU that vests entitles the awardee to one share of Common Stock. RSU awardees do not have any of the rights of a Gartner stockholder, including voting rights and the right to receive dividends and distributions, until the shares are released. The fair value of an RSU award is determined on the date of grant based on the closing price of the Common Stock as reported on the New York Stock Exchange on that date. Service-based RSUs vest ratably over four years and are expensed on a straight-line basis over the vesting period. Performance-based RSUs are subject to the satisfaction of both performance and service conditions, vest ratably over four years and are expensed on an accelerated basis over the vesting period.

The following table summarizes the changes in RSUs outstanding during the three months ended March 31, 2018:



	Restricted Stock Units ("RSUs") (in millions)		Per Share Weighted Average Grant Date Fair Value
Outstanding at December 31, 2017	1.5		$	91.47
Granted (1)	0.7		114.33
Vested and released	(0.6	)	86.21
Outstanding at March 31, 2018 (2) (3)	1.6		$	101.52

(1)

The 0.7 million of RSUs granted during the three months ended March 31, 2018 consisted of 0.3 million of performance-based RSUs awarded to executives and 0.4 million of service-based RSUs awarded to non-executive employees. The performance-based awards include RSUs in final settlement of 2017 grants and approximately 0.2 million of RSUs representing the target amount of the grant for the year ending December 31, 2018 that is tied to an increase in Gartner's total contract value for 2018. Total contract value for this determination represents the value attributable to all of Gartner's subscription-related revenue contracts. The number of performance-based RSUs that will ultimately be awarded for 2018 ranges from 0% to 200% of the target amount and will be finalized based on the actual increase in Gartner's total contract value for 2018 as measured on December 31, 2018. If the specified minimum level of achievement is not met, the performance-based RSUs pertaining to 2018 will be forfeited in their entirety and any previously recorded compensation expense will be reversed.


(2)	The Company expects that substantially all of the RSUs outstanding will vest in future periods.


(3)	As of March 31, 2018, the weighted average remaining contractual term of the RSUs outstanding was approximately 1.8 years.

Common Stock Equivalents

Common stock equivalents ("CSEs") are convertible into Common Stock. Each CSE entitles the holder to one share of Common Stock. Members of our Board of Directors receive their directors’ fees in CSEs unless they opt to receive up to 50% of those fees in cash. Generally, CSEs have no defined term and are converted into shares of Common Stock when service as a director terminates unless the director has elected an accelerated release. The fair value of a CSE award is determined on the date of grant based on the closing price of the Common Stock as reported on the New York Stock Exchange on that date. CSEs vest immediately and, as a result, they are recorded as expense on the date of grant.

The following table summarizes the changes in CSEs outstanding during the three months ended March 31, 2018:



	Common Stock Equivalents ("CSEs")		Per Share Weighted Average Grant Date Fair Value
Outstanding at December 31, 2017	110,013		$	23.19
Granted	1,624		116.06
Converted to shares of Common Stock upon grant	(998	)	124.94
Outstanding at March 31, 2018	110,639		$	23.59

Employee Stock Purchase Plan

The Company has an employee stock purchase plan (the “ESP Plan”) under which eligible employees are permitted to purchase shares of Common Stock through payroll deductions, which may not exceed 10% of an employee’s compensation, or $23,750 in any calendar year, at a price equal to 95% of the closing price of the Common Stock as reported on the New York Stock Exchange at the end of each offering period. As of March 31, 2018, the Company had 0.8 million shares available for purchase under the ESP Plan. The ESP Plan is considered non-compensatory under FASB ASC Topic 718 and, as a result, the Company does not record stock-based compensation expense for employee share purchases. The Company received $4.1 million and $3.0 million in cash from employee share purchases under the ESP Plan during the three months ended March 31, 2018 and 2017, respectively.

Segment Information

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Segment Information

Our products and services are delivered through four segments – Research, Events, Consulting and Talent Assessment & Other, as follows:

•

Research provides trusted, objective insights and advice on the mission-critical priorities of leaders across all functional areas of the enterprise through research and other reports, briefings, proprietary tools, access to our analysts, peer networking services and membership programs that enable our clients to make better decisions. Gartner's traditional strengths in IT, marketing and supply chain research were enhanced in 2017 with Gartner's acquisition of CEB, Inc., which added CEB's best practice and talent management research insights across a range of business functions, to include human resources, finance, sales and legal.


•	Events provides business professionals across the organization the opportunity to learn, share and network. From our flagship CIO event Gartner Symposium/ITxpo, to industry-leading conferences focused on specific business roles and topics, to member-driven sessions, our events enable attendees to experience the best of Gartner insight and advice live.


•	Consulting provides customized solutions to unique client needs through on-site, day-to-day support, as well as proprietary tools for measuring and improving IT performance with a focus on cost, performance, efficiency and quality.


•	Talent Assessment & Other helps organizations assess, engage, manage and improve talent. This is accomplished through knowledge and skills assessments, training programs, workshops, and survey and questionnaire services.

The Company evaluates segment performance and allocates resources based on gross contribution margin. Gross contribution, as presented in the table below, is defined as operating income or loss excluding certain Cost of services and product development expenses, Selling, general and administrative expenses, Depreciation, Amortization of intangibles, and Acquisition and integration charges. Certain bonus and fringe benefit costs included in consolidated Cost of services and product development are not allocated to segment expense. The accounting policies used by the reportable segments are the same as those used by the Company. There are no intersegment revenues. The Company does not identify or allocate assets, including capital expenditures, by reportable segment. Accordingly, assets are not reported by segment because the information is not available by segment and is not reviewed in the evaluation of segment performance or in making decisions in the allocation of resources.

The following tables present operating information about the Company’s reportable segments for the periods indicated (in thousands):



Three Months Ended March 31, 2018	Research		Events		Consulting		Talent Assessment & Other (1)		Consolidated
Revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565
Gross contribution	531,456		16,190		24,124		43,044		614,814
Corporate and other expenses									(623,525		)
Operating loss									$	(8,711	)



Three Months Ended March 31, 2017	Research		Events		Consulting		Talent Assessment & Other		Consolidated
Revenues (2)	$	511,306	$	35,269	$	78,594	$	—	$	625,169
Gross contribution (2)	351,113		13,567		23,937		—		388,617
Corporate and other expenses									(335,103		)
Operating income									$	53,514

(1) In April 2018, the Company sold its CEB Talent Assessment and CEB Workforce Survey and Analytics businesses. These two businesses were acquired in April 2017 with the CEB acquisition. The results of these businesses are included in the Talent Assessment & Other segment results for the three months ended March 31, 2018. Additional information regarding these divestitures is included in Note 2 — Acquisitions and Divestitures.

(2)

In 2017, the Company began reporting the results of its Strategic Advisory Services ("SAS") business in Research whereas previously the SAS business was reported with Consulting. As a result, revenues of $6.7 million pertaining to the three months ended March 31, 2017 were reclassified from Consulting to Research to be comparable with the current year presentation. Gross contribution of $4.4 million for the three months ended March 31, 2017 was also reclassified from Consulting to Research.

The following table provides a reconciliation of total segment gross contribution to net (loss) income for the periods indicated (in thousands):



	Three Months Ended
	March 31,
	2018			2017
Total segment gross contribution	$	614,814		$	388,617
Costs and expenses:
Cost of services and product development - unallocated (1)	8,458			1,057
Selling, general and administrative	487,745			304,244
Depreciation and amortization	68,056			16,530
Acquisition and integration charges	59,266			13,272
Operating (loss) income	(8,711		)	53,514
Interest expense and other, net	34,160			5,017
(Benefit) provision for income taxes	(23,284		)	12,064
Net (loss) income	$	(19,587	)	$	36,433


(1)	The unallocated amounts consist of certain bonus and related fringe costs recorded in consolidated Cost of services and product development expense that are not allocated to segment expense. The Company's policy is to only allocate bonus and related fringe charges to segments for up to 100% of the segment employee's target bonus. Amounts above 100% are absorbed by corporate.

Goodwill and Intangible Assets

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

Goodwill

Goodwill represents the excess of the purchase price of acquired businesses over the estimated fair values of the tangible and identifiable intangible net assets acquired. Evaluations of the recoverability of goodwill are performed in accordance with FASB ASC Topic 350, which requires an annual assessment of potential goodwill impairment at the reporting unit level and whenever events or changes in circumstances indicate that the carrying value of goodwill may not be recoverable. The annual assessment of the recoverability of recorded goodwill can be based on either a qualitative or quantitative assessment or a combination of the two approaches. Both methods utilize estimates which, in turn, require judgments and assumptions regarding future trends and events. As a result, both the precision and reliability of the resulting estimates are subject to uncertainty. If our annual goodwill impairment evaluation determines that the fair value of a reporting unit is less than its related carrying amount, we may recognize an impairment charge. In connection with our most recent annual impairment test of goodwill during the quarter ended September 30, 2017, which indicated no impairment of recorded goodwill, the Company utilized the qualitative approach in assessing the fair values of its reporting units relative to their respective carrying values.

The following table presents changes to the carrying amount of goodwill by segment during the three months ended March 31, 2018 (in thousands):



	Research			Events			Consulting		Talent Assessment & Other			Total
Balance at December 31, 2017 (1), (2)	$	2,619,677		$	187,920		$	97,798	$	81,899		$	2,987,294
Reclassified as held-for-sale (3)	—			—			—		(20,547		)	(20,547		)
Foreign currency translation impact and other (4)	(17,958		)	(170		)	528		7,495			(10,105		)
Balance at March 31, 2018	$	2,601,719		$	187,750		$	98,326	$	68,847		$	2,956,642


(1)	The Company does not have any accumulated goodwill impairment losses.


(2)	Excludes certain amounts related to held-for-sale operations.


(3)	Represents amounts reclassified as held-for-sale assets related to the CEB Talent Assessment and WS&A businesses. See Note 2 — Acquisitions and Divestitures for additional information.


(4)	Includes the foreign currency translation impact and certain measurement period adjustments related to the acquisition of CEB in April 2017.

Finite-Lived Intangible Assets

The following tables present reconciliations of the carrying amounts of the Company's finite-lived intangible assets as of the dates indicated (in thousands):



March 31, 2018	Customer Relationships			Software			Content			Other			Total
Gross cost at December 31, 2017 (1)	$	1,200,316		$	123,424		$	104,313		$	54,929		$	1,482,982
Write-off of fully amortized intangible assets	—			—			(228		)	—			(228		)
Reclassified as held-for-sale (2)	(7,170		)	(321		)	(241		)	(39		)	(7,771		)
Foreign currency translation impact	15,218			491			251			(171		)	15,789
Gross cost	1,208,364			123,594			104,095			54,719			1,490,772
Accumulated amortization (3)	(119,075		)	(32,410		)	(63,778		)	(27,738		)	(243,001		)
Balance at March 31, 2018 (1)	$	1,089,289		$	91,184		$	40,317		$	26,981		$	1,247,771



December 31, 2017	Customer Relationships			Software			Content			Other			Total
Gross cost (1)	$	1,200,316		$	123,424		$	104,313		$	54,929		$	1,482,982
Accumulated amortization (3)	(92,983		)	(26,344		)	(47,475		)	(24,158		)	(190,960		)
Balance at December 31, 2017 (1)	$	1,107,333		$	97,080		$	56,838		$	30,771		$	1,292,022

(1) Excludes amounts related to held-for-sale operations.


(2)	Represents amounts reclassified (net) as held-for-sale assets related to the WS&A business. See Note 2 — Acquisitions and Divestitures for additional information.

(3) Finite-lived intangible assets are amortized using the straight-line method over the following periods: Customer relationships—4 to 13 years; Software—3 to 7 years; Content—1.5 to 5 years; and Other—2 to 5 years.

Amortization expense related to finite-lived intangible assets was $51.6 million and $6.3 million during the three months ended March 31, 2018 and 2017, respectively. The estimated future amortization expense by year for finite-lived intangible assets is as follows (in thousands):



2018 (remaining nine months)	$	138,953
2019	135,868
2020	129,461
2021	108,979
2022	99,363
Thereafter	635,147
	$	1,247,771

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Debt

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Debt

2016 Credit Agreement

The Company has a credit facility that provides for a $1.5 billion Term loan A facility, a $500.0 million Term loan B facility, and a $1.2 billion revolving credit facility (the "2016 Credit Agreement"). The 2016 Credit Agreement contains certain customary restrictive loan covenants, including, among others, financial covenants that apply a maximum leverage ratio and a minimum interest expense coverage ratio, and covenants limiting Gartner’s ability to incur indebtedness, grant liens, make acquisitions, merge, dispose of assets, pay dividends, repurchase stock, make investments and enter into certain transactions with affiliates. The Company was in full compliance with the covenants as of March 31, 2018.

The Term loan A facility is being repaid in 16 consecutive quarterly installments that commenced on June 30, 2017, plus a final payment to be made on March 20, 2022. The revolving credit facility may be borrowed, repaid, and re-borrowed through March 20, 2022, at which time all amounts must be repaid. Amounts borrowed under the Term loan A facility and the revolving credit facility bear interest at a rate equal to, at the Company's option, either:

(i) the greatest of: (x) the Administrative Agent’s prime rate; (y) the average rate on Federal Reserve Board of New York rate plus 1/2 of 1%; and (z) the eurodollar rate (adjusted for statutory reserves) plus 1%, in each case plus a margin equal to between 0.125% and 1.50% depending on Gartner’s consolidated leverage ratio as of the end of the four consecutive fiscal quarters most recently ended; or

(ii) the eurodollar rate (adjusted for statutory reserves) plus a margin equal to between 1.125% and 2.50%, depending on Gartner’s leverage ratio as of the end of the four consecutive fiscal quarters most recently ended.

The Term loan B facility will mature on April 5, 2024 and amounts outstanding thereunder will bear interest at a rate per annum equal to, at the option of Gartner, (i) adjusted LIBOR plus 2.00% or (ii) an alternate base rate plus 1.00%. The Term loan B facility is being repaid in 28 consecutive quarterly installments that commenced on June 30, 2017, plus a final payment to be made on April 5, 2024.

Senior Notes

The Company has $800.0 million aggregate principal amount of 5.125% Senior Notes due 2025 (the “Senior Notes”). The Senior Notes were issued at an issue price of 100.00% and bear interest at a fixed rate of 5.125% per annum. Interest on the Senior Notes is payable on April 1 and October 1 of each year. The Senior Notes will mature on April 1, 2025.

The Company may redeem some or all of the Senior Notes at any time on or after April 1, 2020 for cash at the redemption prices set forth in the Note Indenture, plus accrued and unpaid interest to, but not including, the redemption date. Prior to April 1, 2020, the Company may redeem up to 40% of the aggregate principal amount of the Senior Notes with the proceeds of certain equity offerings at a redemption price of 105.125% plus accrued and unpaid interest to, but not including, the redemption date. In addition, the Company may redeem some or all of the Senior Notes prior to April 1, 2020, at a redemption price of 100% of the principal amount of the Senior Notes plus accrued and unpaid interest to, but not including, the redemption date, plus a “make-whole” premium. If the Company experiences specific kinds of change of control, it will be required to offer to purchase the Senior Notes at a price equal to 101% of the principal amount thereof plus accrued and unpaid interest.

Outstanding Borrowings

The following table summarizes the Company’s total outstanding borrowings as of the dates indicated (in thousands):



	March 31,			December 31,
Description:	2018			2017
2016 Credit Agreement - Term loan A facility (1)	$	1,410,750		$	1,429,312
2016 Credit Agreement - Term loan B facility (1)	495,000			496,250
2016 Credit Agreement - Revolving credit facility (1), (2)	310,000			595,000
Senior Notes (3)	800,000			800,000
Other (4)	2,385			2,500
Principal amount outstanding (5)	$	3,018,135		$	3,323,062
Less: deferred financing fees (6)	(42,350		)	(44,217		)
Net balance sheet carrying amount (7)	$	2,975,785		$	3,278,845

(1)

The contractual annualized interest rate as of March 31, 2018 on the Term loan A and B facilities was 3.88%, which consisted of a floating eurodollar base rate of 1.88% plus a margin of 2.00%. The contractual annualized interest rate on the revolving credit facility was 4.38%, which consisted of a floating eurodollar base rate of 1.88% plus a margin of 2.50%. However, the Company has interest rate swap contracts which effectively convert the floating eurodollar base rates on a portion of the amounts outstanding to a fixed base rate.


(2)	The Company had $866.0 million of available borrowing capacity on the revolver (not including the expansion feature) as of March 31, 2018.


(3)	Consists of $800.0 million principal amount of Senior Notes outstanding. The Senior Notes pay a fixed rate of 5.125% and mature on April 1, 2025.


(4)	Consists of a $2.5 million State of Connecticut economic development loan with a 3.00% fixed rate of interest. The loan was originated in 2012 and has a 10 year maturity. Principal payments are deferred for the first five years and the loan may be repaid at any time by the Company without penalty.


(5)	The average annual effective rate on the Company's total debt outstanding for the three months ended March 31, 2018, including the effect of its interest rate swaps discussed below, was 4.14%.


(6)	The deferred financing fees are being amortized to Interest expense, net over the term of the related debt obligation.


(7)	On April 30, 2018, the Company repaid $400.0 million of the Term loan B facility and $50.0 million of the revolving credit facility.

Interest Rate Swaps

The Company has fixed-for-floating interest rate swap contracts which it designates as accounting hedges of the forecasted interest payments on the Company’s variable rate borrowings. The Company pays base fixed rates on the swaps and in return receives a floating eurodollar base rate on 30 day notional borrowings. The Company accounts for the interest rate swaps as cash flow hedges in accordance with FASB ASC Topic 815. Since the swaps hedge forecasted interest payments, changes in the fair value of the swaps are recorded in accumulated other comprehensive income (loss), a component of equity, as long as the swaps continue to be highly effective hedges of the designated interest rate risk. Any ineffective portion of change in the fair value of the hedges is recorded in earnings. All of the Company's swaps were highly effective hedges of the forecasted interest payments as of March 31, 2018. The interest rate swaps had a total positive fair value (asset) to the Company of $17.3 million at March 31, 2018, which is deferred and recorded in Accumulated other comprehensive income, net of tax effect.

Equity

3 Months Ended

Mar. 31, 2018

Stockholders' Equity Note [Abstract]

Equity

Share Repurchase Authorization

The Company has a $1.2 billion board approved authorization to repurchase the Company's common stock, of which $1.1 billion remained available as of March 31, 2018. The Company may repurchase its common stock from time to time in amounts and at prices the Company deems appropriate, subject to the availability of stock, prevailing market conditions, the trading price of the stock, the Company’s financial performance and other conditions. Repurchases may be made through open market purchases, private transactions or other transactions and will be funded from cash on hand and borrowings under the Company’s credit arrangement.

The Company’s recent share repurchase activity is presented in the following table:



	Three Months Ended
	March 31,
	2018		2017
Number of shares repurchased (1), (2)	239,268		218,752
Cash paid for repurchased shares (in thousands)	$	28,394	$	21,978

(1) The average purchase price for repurchased shares was $118.73 and $100.47 for the three months ended March 31, 2018 and 2017, respectively.

(2) All of the shares repurchased in both quarterly periods related to the settlement of the Company's share-based compensation awards.

Accumulated Other Comprehensive Income (Loss), net ("AOCI/L")

The following tables disclose information about changes in AOCI/L by component and the related amounts reclassified out of AOCI/L to income during the periods indicated (net of tax, in thousands) (1):

For the three months ended March 31, 2018:



	Interest Rate Swaps		Defined Benefit Pension Plans			Foreign Currency Translation Adjustments		Total
Balance – December 31, 2017	$	2,483	$	(5,861	)	$	4,886	$	1,508
Changes during the period:
Change in AOCI/L before reclassifications to income	9,365		—			20,547		29,912
Reclassifications from AOCI/L to income during the period (2), (3)	749		56			—		805
Other comprehensive income for the period	10,114		56			20,547		30,717
Balance – March 31, 2018	$	12,597	$	(5,805	)	$	25,433	$	32,225

For the three months ended March 31, 2017:



	Interest Rate Swaps			Defined Benefit Pension Plans			Foreign Currency Translation Adjustments			Total
Balance – December 31, 2016	$	(1,409	)	$	(5,797	)	$	(42,477	)	$	(49,683	)
Changes during the period:
Change in AOCI/L before reclassifications to income	(3,393		)	—			4,371			978
Reclassifications from AOCI/L to income during the period (2), (3)	825			48			—			873
Other comprehensive income (loss) for the period	(2,568		)	48			4,371			1,851
Balance – March 31, 2017	$	(3,977	)	$	(5,749	)	$	(38,106	)	$	(47,832	)


(1)	Amounts in parentheses represent debits (deferred losses).


(2)	The reclassifications related to interest rate swaps (cash flow hedges) were recorded in Interest expense, net of tax effect. See Note 10 – Derivatives and Hedging for information regarding the hedges.


(3)	The reclassifications related to defined benefit pension plans were recorded in Selling, general and administrative expense, net of tax effect. See Note 12 – Employee Benefits for information regarding the Company’s defined benefit pension plans.

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes for the three months ended March 31, 2018 was a benefit of $(23.3) million on a pretax loss of $(42.9) million compared to an expense of $12.1 million on pretax income of $48.5 million in the three months ended March 31, 2017. The effective income tax rate was 54.3% for the three months ended March 31, 2018 and 24.9% for the same period in 2017. The quarter-over-quarter change in the effective income tax rate was primarily attributable to the relative impact of stock-based compensation benefits quarter-over-quarter. The tax benefits from stock-based compensation during the first quarter of 2018 increased the tax rate on pretax losses while such benefits in the first quarter of 2017 decreased the tax rate on pretax income. In addition to the impact of stock-based compensation, the change in the effective income tax rate quarter-over-quarter was driven by a reduction in the U.S. tax rate effective for 2018 as well as tax benefits recognized in 2018 for unrealized capital losses on the divestiture of the CEB Talent Assessment business. The Tax Cuts and Jobs Act (the "Act”) was enacted on December 22, 2017. Among other things, the Act reduces the U.S. federal corporation tax rate from 35% to 21%, requires companies to pay a one-time transition tax on accumulated deferred foreign income (“ADFI”) of foreign subsidiaries that were previously tax deferred and creates a new tax on global intangible low-taxed income (“GILTI”) attributable to foreign subsidiaries. As of March 31, 2018, we have not completed our accounting for the tax effects of enactment of the Act because all of the necessary information is not currently available, prepared or analyzed. As such, the amounts we have recorded are provisional estimates and as permitted by the SEC per Staff Accounting Bulletin No. 118. We expect to complete the accounting for the impact of tax reform by the fourth quarter of 2018 as we complete our analysis and receive additional guidance from the Internal Revenue Service pertaining to the Act. Companies have the option to account for the GILTI tax as a period cost in the period incurred, or to recognize deferred taxes for temporary differences including outside basis differences expected to reverse as a result of the GILTI provisions. The Company has not yet determined its policy election with respect to GILTI. We have, however, included an estimate of the current year GILTI impact in the 2018 tax provision calculation. Upon enactment of the Act, we remeasured U.S. deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is generally 21% and recorded a provisional amount which reduced our 2017 income tax expense by $123.2 million. We are still analyzing certain aspects of the Act and refining our deferred tax calculations, which could affect the measurement of these balances or give rise to new deferred tax amounts. We did not adjust the initial provisional amount in the three months ended March 31, 2018. The tax on ADFI is based on post-1986 earnings and profits ("E&P") of our foreign subsidiaries that were previously deferred from U.S. income taxes. We recorded a provisional amount for this one-time transition tax liability, resulting in an increase in income tax expense of $63.6 million in 2017. We have not yet completed our calculation of the tax on ADFI given the need to obtain, prepare and analyze various information relevant to such calculation including, but not limited to, our post-1986 E&P, foreign taxes and amounts held in cash or other specified assets on various measurement dates. We did not adjust the initial provisional amount in the three months ended March 31, 2018. As of March 31, 2018 and December 31, 2017, the Company had gross unrecognized tax benefits of $63.2 million and $60.3 million, respectively. It is reasonably possible that gross unrecognized tax benefits will decrease by approximately $8.0 million within the next 12 months, due to the anticipated closure of audits and the expiration of certain statutes of limitation. In July 2015, the United States Tax Court (the “Court”) issued an opinion relating to the treatment of stock-based compensation expense in an inter-company cost-sharing arrangement. In its opinion, the Court held that affiliated companies may exclude stock-based compensation expense from their cost-sharing arrangement. The Internal Revenue Service is appealing the decision. Because of uncertainty related to the final resolution of this litigation and the recognition of potential benefits to the Company, the Company has not recorded any financial statement benefit associated with this decision. The Company will monitor developments related to this case and the potential impact of those developments on the Company’s consolidated financial statements.

Derivatives and Hedging

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivatives and Hedging

The Company enters into a limited number of derivative contracts to mitigate the cash flow risk associated with changes in interest rates on variable rate debt and changes in foreign exchange rates on forecasted foreign currency transactions. The Company accounts for its outstanding derivative contracts in accordance with FASB ASC Topic 815, which requires all derivatives, including derivatives designated as accounting hedges, to be recorded on the balance sheet at fair value. The following tables provide information regarding the Company’s outstanding derivatives contracts as of the dates indicated (in thousands, except for number of outstanding contracts):



March 31, 2018
Derivative Contract Type	Number of Outstanding Contracts	Notional Amounts		Fair Value Asset (Liability), Net (3)			Balance Sheet Line Item	Unrealized Gain Recorded in AOCI/L
Interest rate swaps (1)	5	$	1,400,000	$	17,314		Other assets	$	12,597
Foreign currency forwards (2)	46	313,425		(495		)	Accrued liabilities	—
Total	51	$	1,713,425	$	16,819			$	12,597



December 31, 2017
Derivative Contract Type	Number of Outstanding Contracts	Notional Amounts		Fair Value Asset (Liability), Net (3)		Balance Sheet Line Item	Unrealized Gain Recorded in AOCI/L
Interest rate swaps (1)	5	$	1,400,000	$	3,412	Other assets	$	2,483
Foreign currency forwards (2)	137	686,764		448		Other current assets	—
Total	142	$	2,086,764	$	3,860		$	2,483


(1)	The swaps have been designated and are accounted for as cash flow hedges of the forecasted interest payments on borrowings. As a result, changes in the fair value of the swaps are deferred and recorded in AOCI/L, net of tax effect (see Note 7 — Debt for additional information).

(2)

The Company has foreign exchange transaction risk since it typically enters into transactions in the normal course of business that are denominated in foreign currencies that differ from the local functional currency. The Company enters into short-term foreign currency forward exchange contracts to mitigate the cash flow risk associated with changes in foreign currency rates on forecasted foreign currency transactions. These contracts are accounted for at fair value with realized and unrealized gains and losses recognized in Other income, net since the Company does not designate these contracts as hedges for accounting purposes. All of the outstanding contracts at March 31, 2018 matured by the end of April 2018.


(3)	See Note 11 — Fair Value Disclosures for the determination of the fair value of these instruments.

At March 31, 2018, all of the Company’s derivative counterparties were investment grade financial institutions. The Company did not have any collateral arrangements with its derivative counterparties, and none of the derivative contracts contained credit-risk related contingent features. The following table provides information regarding amounts recognized in the Condensed Consolidated Statements of Operations for derivative contracts for the periods indicated (in thousands):



	Three Months Ended
	March 31,
Amount recorded in:	2018			2017
Interest expense (1)	$	945		$	1,375
Other (gain) loss, net (2)	(7,232		)	219
Total (income) expense, net	$	(6,287	)	$	1,594


(1)	Consists of interest expense from interest rate swap contracts.


(2)	Consists of net realized and unrealized gains and losses on foreign currency forward contracts.

Fair Value Disclosures

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Disclosures

The Company’s financial instruments include cash equivalents, fees receivable from customers, accounts payable, and accruals which are normally short-term in nature. The Company believes the carrying amounts of these financial instruments reasonably approximate their fair value due to their short-term nature. The Company’s financial instruments also include its outstanding variable-rate borrowings under the 2016 Credit Agreement. The Company believes the carrying amount of its variable-rate borrowings reasonably approximates their fair value because the rate of interest on those borrowings reflects current market rates of interest for similar instruments with comparable maturities.

The Company enters into a limited number of derivatives transactions but does not enter into repurchase agreements, securities lending transactions, or master netting arrangements. Receivables or payables that result from derivatives transactions are recorded gross in the Company's consolidated balance sheets.

FASB ASC Topic 820 provides a framework for the measurement of fair value and a valuation hierarchy based upon the transparency of inputs used in the valuation of assets and liabilities. Classification within the hierarchy is based upon the lowest level of input that is significant to the resulting fair value measurement. The valuation hierarchy contains three levels. Level 1 measurements consist of quoted prices in active markets for identical assets or liabilities. Level 2 measurements include significant other observable inputs such as quoted prices for similar assets or liabilities in active markets; identical assets or liabilities in inactive markets; observable inputs such as interest rates and yield curves; and other market-corroborated inputs. Level 3 measurements include significant unobservable inputs, such as internally-created valuation models. The Company does not currently utilize Level 3 valuation inputs to remeasure any of its assets or liabilities. However, Level 3 inputs may be used by the Company in its required annual impairment review of recorded goodwill. Information regarding the periodic assessment of the Company’s goodwill is included in Note 6 — Goodwill and Intangible Assets. The Company does not typically transfer assets or liabilities between different levels of the fair value hierarchy.

The following table presents the fair value of certain financial assets and liabilities (in thousands):



Description:	March 31, 2018		December 31, 2017
Assets:
Values based on Level 1 inputs:
Deferred compensation plan assets (1)	$	16,746	$	29,108
Total Level 1 inputs	16,746		29,108
Values based on Level 2 inputs:
Deferred compensation plan assets (1)	59,477		59,017
Foreign currency forward contracts (2)	156		2,053
Interest rate swap contracts (3)	17,314		3,412
Total Level 2 inputs	76,947		64,482
Total Assets	$	93,693	$	93,590
Liabilities:
Values based on Level 2 inputs:
Deferred compensation plan liabilities (1)	$	73,172	$	89,900
Foreign currency forward contracts (2)	651		1,605
Senior Notes due 2025 (4)	801,640		837,560
Total Level 2 inputs	875,463		929,065
Total Liabilities	$	875,463	$	929,065

(1)

The Company has a deferred compensation plan for the benefit of certain highly compensated officers, managers and other key employees. The assets consist of investments in money market and mutual funds, and company-owned life insurance contracts, all of which are valued based on Level 1 or Level 2 valuation inputs. The related deferred compensation plan liabilities are recorded at fair value, or the estimated amount needed to settle the liability, which the Company considers to be a Level 2 input.


(2)	The Company enters into foreign currency forward exchange contracts to hedge the effects of adverse fluctuations in foreign currency exchange rates (see Note 10 - Derivatives and Hedging). Valuation of the foreign currency forward contracts is based on observable foreign currency exchange rates in active markets, which the Company considers a Level 2 input.

(3)

The Company has interest rate swap contracts which hedge the risk of variability from interest payments on its borrowings (see Note 7 — Debt). The fair value of the swaps is based on mark-to-market valuations prepared by a third-party broker. The valuations are based on observable interest rates from recently executed market transactions and other observable market data, which the Company considers Level 2 inputs. The Company independently corroborates the reasonableness of the valuations prepared by the third-party broker through the use of an electronic quotation service.


(4)	As discussed in Note 7 — Debt, the Company has $800.0 million of principal amount fixed-rate Senior Notes due in 2025. The estimated fair value of the notes was derived from quoted market prices provided by an independent dealer which the Company considers to be a Level 2 input.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Employee Benefits	3 Months Ended
Employee Benefits	Mar. 31, 2018
Retirement Benefits [Abstract]
Employee Benefits	Employee Benefits Defined-Benefit Pension Plans The Company has defined-benefit pension plans in several of its international locations. Benefits paid under these plans are based on years of service and level of employee compensation. The Company’s defined-benefit pension plans are accounted for in accordance with FASB ASC Topics 715 and 960. Net periodic pension expense was $0.7 million for both the three months ended March 31, 2018 and 2017.

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contingencies The Company is involved in legal proceedings and litigation arising in the ordinary course of business. We believe that the potential liability, if any, in excess of amounts already accrued from all proceedings, claims and litigation will not have a material effect on our financial position, cash flows, or results of operations when resolved in a future period. The Company has various agreements that may obligate us to indemnify the other party with respect to certain matters. Generally, these indemnification clauses are included in contracts arising in the normal course of business under which we customarily agree to hold the other party harmless against losses arising from a breach of representations related to such matters as title to assets sold and licensed or certain intellectual property rights. It is not possible to predict the maximum potential amount of future payments under these indemnification agreements due to the conditional nature of the Company’s obligations and the unique facts of each particular agreement. Historically, payments made by us under these agreements have not been material. As of March 31, 2018, the Company did not have any material payment obligations under any such indemnification agreements.

Subsequent Event	3 Months Ended
Subsequent Event	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events In April 2018, the Company sold its CEB Talent Assessment and CEB Workforce Survey and Analytics businesses. These two businesses were acquired in April 2017 with the CEB acquisition and were reported by the Company in the Talent Assessment & Other segment. Additional information regarding these divestitures is included in Note 2 — Acquisitions and Divestitures. In addition, on April 30, 2018, the Company repaid $450.0 million of its outstanding debt. Note 7 — Debt provides additional information regarding the Company's debt obligations.

Business and Basis of Presentation (Policies)

3 Months Ended

Mar. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of presentation

Principles of consolidation

Use of estimates

Adoption of new accounting standards and Accounting standards issued but not yet adopted

Adoption of new accounting standards. The Company adopted the accounting standards described below during the three months ended March 31, 2018:



	March 31,				December 31,
	2018		2017		2017		2016
Cash and cash equivalents	$	189,979	$	1,227,891	$	538,908	$	474,233
Restricted cash classified in (1), (2):
Prepaid expenses and other current assets	18,143		25,121		15,148		25,121
Other assets	—		18,150		3,002		—
Cash classified as held-for-sale (3)	19,508		—		10,000		—
Cash and cash equivalents and restricted cash per the Condensed Consolidated Statements of Cash Flows	$	227,630	$	1,271,162	$	567,058	$	499,354

(1)


(2)	Restricted cash is recorded in Prepaid expenses and other current assets and Other assets in the Company's consolidated balance sheets with the short-term or long-term classification dependent on the projected timing of disbursements to the sellers.


(3)	Represents cash classified as a held-for-sale asset for certain businesses that were acquired as part of the CEB acquisition. See Note 2 — Acquisitions and Divestitures for additional information.

Accounting standards effective in 2019

Accounting standards effective in 2020

Revenue Recognition

Our business and our revenues

Research

Events

Consulting

Talent Assessment & Other

Overview of ASU No. 2014-09

ASU No. 2014-09 requires a five-step evaluative process that consists of:


(1)	Identifying the contract with the customer;


(2)	Identifying the performance obligations in the contract;


(3)	Determining the transaction price for the contract;


(4)	Allocating the transaction price to the performance obligations in the contract; and


(5)	Recognizing revenue when (or as) performance obligations are satisfied.

Required Disclosures under ASU No. 2014-09

Disaggregated Revenues

Three Months Ended March 31, 2018



	Research		Events		Consulting		Talent Assessment & Other		Total
Primary Geographic Markets: (1)
United States and Canada	$	489,713	$	24,069	$	45,129	$	34,594	$	593,505
Europe, Middle East and Africa	184,547		16,891		29,938		28,290		259,666
Other International	89,664		5,127		7,829		7,774		110,394
Total revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565

Three Months Ended March 31, 2017



	Research		Events		Consulting		Talent Assessment & Other		Total
Primary Geographic Markets: (1)
United States and Canada	$	327,492	$	17,663	$	47,832	$	—	$	392,987
Europe, Middle East and Africa	115,802		14,095		23,823		—		153,720
Other International	68,012		3,511		6,939		—		78,462
Total revenues	$	511,306	$	35,269	$	78,594	$	—	$	625,169


(1)	Revenues are reported based on where the sale is fulfilled.

Three Months Ended March 31, 2018



	Research		Events		Consulting		Talent Assessment & Other		Total
Timing of Revenue Recognition:
Transferred over time (1)	$	701,096	$	—	$	74,010	$	58,946	$	834,052
Transferred at a point in time (2)	62,828		46,087		8,886		11,712		129,513
Total revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565

Three Months Ended March 31, 2017



	Research		Events		Consulting		Talent Assessment & Other		Total
Timing of Revenue Recognition:
Transferred over time (1)	$	466,706	$	—	$	64,994	$	—	$	531,700
Transferred at a point in time (2)	44,600		35,269		13,600		—		93,469
Total revenues	$	511,306	$	35,269	$	78,594	$	—	$	625,169

(1)


(2)	The revenues in this category were recognized in connection with performance obligations that were satisfied at the point in time the contractual deliverables were provided to the customer.

Customer Contract Assets and Liabilities

The table below provides information regarding certain of the Company’s balance sheet accounts that pertain to its contracts with customers, to exclude our held-for-sale businesses (in thousands):



	March 31,		December 31,
	2018		2017
Assets:
Fees receivable, gross (1)	$	1,142,064	$	1,162,871

Contract assets (2)	$	27,593	$	26,672

Contract liabilities:
Deferred revenues (current liability) (3)	$	1,719,637	$	1,630,198
Non-current deferred revenues (3)	16,139		16,205
Total contract liabilities	$	1,735,776	$	1,646,403


(1)	Fees receivable represent the unconditional right of payment from our customers and includes both billed and unbilled amounts.

(2)


(3)	Deferred revenues represent amounts (i) for which the Company has received an upfront customer payment or (ii) that pertain to recognized fees receivable. Both situations occur before the completion of our performance obligation(s).

Allowance for Losses and Revenue Reserves

Costs of obtaining and fulfilling a customer contract

Acquisitions

Business and Basis of Presentation Business and Basis of Presentation (Tables)

3 Months Ended

Mar. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Cash and Cash Equivalents

Below is a table reconciling the beginning-of-period and end-of-period total cash amounts included in the Condensed Consolidated Balance Sheets to the amounts presented in the Condensed Consolidated Cash Flow Statements (in thousands).



	March 31,				December 31,
	2018		2017		2017		2016
Cash and cash equivalents	$	189,979	$	1,227,891	$	538,908	$	474,233
Restricted cash classified in (1), (2):
Prepaid expenses and other current assets	18,143		25,121		15,148		25,121
Other assets	—		18,150		3,002		—
Cash classified as held-for-sale (3)	19,508		—		10,000		—
Cash and cash equivalents and restricted cash per the Condensed Consolidated Statements of Cash Flows	$	227,630	$	1,271,162	$	567,058	$	499,354

(1)


(2)	Restricted cash is recorded in Prepaid expenses and other current assets and Other assets in the Company's consolidated balance sheets with the short-term or long-term classification dependent on the projected timing of disbursements to the sellers.


(3)	Represents cash classified as a held-for-sale asset for certain businesses that were acquired as part of the CEB acquisition. See Note 2 — Acquisitions and Divestitures for additional information.

Schedule of Restricted Cash



	March 31,				December 31,
	2018		2017		2017		2016
Cash and cash equivalents	$	189,979	$	1,227,891	$	538,908	$	474,233
Restricted cash classified in (1), (2):
Prepaid expenses and other current assets	18,143		25,121		15,148		25,121
Other assets	—		18,150		3,002		—
Cash classified as held-for-sale (3)	19,508		—		10,000		—
Cash and cash equivalents and restricted cash per the Condensed Consolidated Statements of Cash Flows	$	227,630	$	1,271,162	$	567,058	$	499,354

(1)


(2)	Restricted cash is recorded in Prepaid expenses and other current assets and Other assets in the Company's consolidated balance sheets with the short-term or long-term classification dependent on the projected timing of disbursements to the sellers.


(3)	Represents cash classified as a held-for-sale asset for certain businesses that were acquired as part of the CEB acquisition. See Note 2 — Acquisitions and Divestitures for additional information.

Schedule of Disaggregation of Revenue by Reportable Segment

Our disaggregated revenue information by reportable segment is presented for the periods indicated in the tables below (in thousands).

Three Months Ended March 31, 2018



	Research		Events		Consulting		Talent Assessment & Other		Total
Primary Geographic Markets: (1)
United States and Canada	$	489,713	$	24,069	$	45,129	$	34,594	$	593,505
Europe, Middle East and Africa	184,547		16,891		29,938		28,290		259,666
Other International	89,664		5,127		7,829		7,774		110,394
Total revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565

Three Months Ended March 31, 2017



	Research		Events		Consulting		Talent Assessment & Other		Total
Primary Geographic Markets: (1)
United States and Canada	$	327,492	$	17,663	$	47,832	$	—	$	392,987
Europe, Middle East and Africa	115,802		14,095		23,823		—		153,720
Other International	68,012		3,511		6,939		—		78,462
Total revenues	$	511,306	$	35,269	$	78,594	$	—	$	625,169


(1)	Revenues are reported based on where the sale is fulfilled.

Schedule of Disaggregation of Revenue

Three Months Ended March 31, 2018



	Research		Events		Consulting		Talent Assessment & Other		Total
Timing of Revenue Recognition:
Transferred over time (1)	$	701,096	$	—	$	74,010	$	58,946	$	834,052
Transferred at a point in time (2)	62,828		46,087		8,886		11,712		129,513
Total revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565

Three Months Ended March 31, 2017



	Research		Events		Consulting		Talent Assessment & Other		Total
Timing of Revenue Recognition:
Transferred over time (1)	$	466,706	$	—	$	64,994	$	—	$	531,700
Transferred at a point in time (2)	44,600		35,269		13,600		—		93,469
Total revenues	$	511,306	$	35,269	$	78,594	$	—	$	625,169

(1)


(2)	The revenues in this category were recognized in connection with performance obligations that were satisfied at the point in time the contractual deliverables were provided to the customer.

Schedule for Contract with Customer, Asset and Liability

The table below provides information regarding certain of the Company’s balance sheet accounts that pertain to its contracts with customers, to exclude our held-for-sale businesses (in thousands):



	March 31,		December 31,
	2018		2017
Assets:
Fees receivable, gross (1)	$	1,142,064	$	1,162,871

Contract assets (2)	$	27,593	$	26,672

Contract liabilities:
Deferred revenues (current liability) (3)	$	1,719,637	$	1,630,198
Non-current deferred revenues (3)	16,139		16,205
Total contract liabilities	$	1,735,776	$	1,646,403


(1)	Fees receivable represent the unconditional right of payment from our customers and includes both billed and unbilled amounts.

(2)


(3)	Deferred revenues represent amounts (i) for which the Company has received an upfront customer payment or (ii) that pertain to recognized fees receivable. Both situations occur before the completion of our performance obligation(s).

Acquisitions and Divestitures (Tables)

3 Months Ended

Mar. 31, 2018

Business Combinations [Abstract]

Summary of amounts related to new building

The following table presents a summary of the activity related to our accrual for exit costs at all of our facilities for the quarter ended March 31, 2018 (in thousands):



Liability balance at December 31, 2017	$	12,961
Charges and adjustments, net	44,230
Payments	(4,734		)
Liability balance at March 31, 2018 (1)	$	52,457


(1)	In total, we estimate that we will make net cash payments of approximately $61.2 million for exit costs in connection with the activities described herein. Through March 31, 2018, in the aggregate, we have expensed $57.3 million and paid $4.9 million related to such activities.

Principal components of held-for-sale assets and liabilities

The principal components of the held-for-sale assets and liabilities for these businesses are summarized in the table below (in thousands):



	March 31, 2018 (1)		December 31, 2017 (1)
Cash and cash equivalents	$	19,508	$	10,000
Fees receivable, net	49,191		50,928
Goodwill	246,661		212,994
Intangible assets, net	264,145		250,472
Other assets (2)	23,849		18,571
Total assets held-for-sale	$	603,354	$	542,965

Accounts payable and accrued liabilities	$	26,467	$	32,388
Deferred revenues	65,846		61,450
Other liabilities	51,644		52,007
Total liabilities held-for-sale	$	143,957	$	145,845

(1) March 31, 2018 includes both the CEB Talent Assessment business and the WS&A business. December 31, 2017 includes the CEB Talent Assessment business only.

(2) Other assets includes property, equipment and leasehold improvements, net.

- Definition

Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65878427&loc=SL51721533-107759

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721665-107760

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1474-107760

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721683-107760

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=84176398&loc=SL51724579-110230

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5C
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721675-107760

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721663-107760

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84176398&loc=d3e2941-110230

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721659-107760

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721671-107760

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5D
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721677-107760

+ Details

Computation of Net (Loss) Income per Share (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Schedule of basic and diluted (loss) earnings per share calculations

The following table sets forth the calculation of basic and diluted (loss) income per share (in thousands, except per share data):



	Three Months Ended
	March 31,
	2018			2017
Numerator:
Net (loss) income used for calculating basic and diluted (loss) income per common share	$	(19,587	)	$	36,433

Denominator:
Weighted average common shares used in the calculation of basic (loss) income per share	91,005			82,835
Common stock equivalents associated with stock-based compensation plans (1), (2)	—			1,260
Shares used in the calculation of diluted (loss) income per share	91,005			84,095

Basic (loss) income per share	$	(0.22	)	$	0.44
Diluted (loss) income per share	$	(0.22	)	$	0.43


(1)	For the three months ended March 31, 2017, certain common stock equivalents were not included in the computation of diluted income per share because the effect would have been anti-dilutive. These common share equivalents totaled less than 0.4 million for the 2017 period presented.


(2)	For the three months ended March 31, 2018, approximately 1.3 million common stock equivalents were completely excluded from the calculation of diluted (loss) per share because they were anti-dilutive.

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of stock-based compensation expense by award type

The Company recognized the following stock-based compensation expense by award type and expense category line item during the periods indicated (in millions):



	Three Months Ended
	March 31,
Award type	2018		2017
Stock appreciation rights	$	3.5	$	2.8
Restricted stock units	27.2		19.6
Common stock equivalents	0.2		0.2
Total (1)	$	30.9	$	22.6

Schedule of stock-based compensation expense by expense category



	Three Months Ended
	March 31,
Expense category line item	2018		2017
Cost of services and product development	$	11.4	$	9.3
Selling, general and administrative	18.2		13.3
Acquisition and integration charges (2)	1.3		—
Total (1)	$	30.9	$	22.6

(2) These charges are primarily the result of the acceleration of the vesting of certain restricted stock units related to the CEB acquisition.

Schedule of fair value assumptions of SARs

The fair value of a SARs award is determined on the date of grant using the Black-Scholes-Merton valuation model with the following weighted average assumptions:



	Three Months Ended
	March 31,
	2018		2017
Expected dividend yield (1)	—	%	—	%
Expected stock price volatility (2)	21	%	22	%
Risk-free interest rate (3)	2.5	%	1.8	%
Expected life in years (4)	4.5		4.5


(1)	The expected dividend yield assumption was based on both the Company's historical and anticipated dividend payouts. Historically, the Company has not paid cash dividends on its Common Stock.


(2)	The determination of expected stock price volatility was based on both historical Common Stock prices and implied volatility from publicly traded options in the Common Stock.


(3)	The risk-free interest rate was based on the yield of a U.S. Treasury security with a maturity similar to the expected life of the award.


(4)	The expected life represents the Company’s estimate of the weighted average period of time the SARs are expected to be outstanding (that is, the period between the service inception date and the expected exercise date).

Stock appreciation rights

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of summary of the changes in SARS, RSUs, and CSEs outstanding

The following table summarizes changes in SARs outstanding during the three months ended March 31, 2018:



	Stock Appreciation Rights ("SARs") (in millions)	Per Share Weighted Average Exercise Price		Per Share Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (Years)
Outstanding at December 31, 2017	1.2	$	76.73	$	17.35	4.28
Granted	0.3	114.26		25.63		6.86
Outstanding at March 31, 2018 (1) (2)	1.5	85.06		19.15		4.70
Vested and exercisable at March 31, 2018 (2)	0.8	$	70.96	$	16.39	3.56

(1) As of March 31, 2018, 0.7 million of the total SARs outstanding were unvested. The Company expects that substantially all of those unvested awards will vest in future periods.

(2) As of March 31, 2018, the total SARs outstanding had an intrinsic value of $47.6 million. On such date, SARs vested and exercisable had an intrinsic value of $35.1 million.

Restricted stock units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of summary of the changes in SARS, RSUs, and CSEs outstanding

The following table summarizes the changes in RSUs outstanding during the three months ended March 31, 2018:



	Restricted Stock Units ("RSUs") (in millions)		Per Share Weighted Average Grant Date Fair Value
Outstanding at December 31, 2017	1.5		$	91.47
Granted (1)	0.7		114.33
Vested and released	(0.6	)	86.21
Outstanding at March 31, 2018 (2) (3)	1.6		$	101.52

(1)


(2)	The Company expects that substantially all of the RSUs outstanding will vest in future periods.


(3)	As of March 31, 2018, the weighted average remaining contractual term of the RSUs outstanding was approximately 1.8 years.

Common stock equivalents

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of summary of the changes in SARS, RSUs, and CSEs outstanding

The following table summarizes the changes in CSEs outstanding during the three months ended March 31, 2018:



	Common Stock Equivalents ("CSEs")		Per Share Weighted Average Grant Date Fair Value
Outstanding at December 31, 2017	110,013		$	23.19
Granted	1,624		116.06
Converted to shares of Common Stock upon grant	(998	)	124.94
Outstanding at March 31, 2018	110,639		$	23.59

Segment Information (Tables)

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Schedule of segment reporting information, by segment

The following tables present operating information about the Company’s reportable segments for the periods indicated (in thousands):



Three Months Ended March 31, 2018	Research		Events		Consulting		Talent Assessment & Other (1)		Consolidated
Revenues	$	763,924	$	46,087	$	82,896	$	70,658	$	963,565
Gross contribution	531,456		16,190		24,124		43,044		614,814
Corporate and other expenses									(623,525		)
Operating loss									$	(8,711	)



Three Months Ended March 31, 2017	Research		Events		Consulting		Talent Assessment & Other		Consolidated
Revenues (2)	$	511,306	$	35,269	$	78,594	$	—	$	625,169
Gross contribution (2)	351,113		13,567		23,937		—		388,617
Corporate and other expenses									(335,103		)
Operating income									$	53,514

(2)

Schedule of reconciliation of segment gross contribution to net income (loss)

The following table provides a reconciliation of total segment gross contribution to net (loss) income for the periods indicated (in thousands):



	Three Months Ended
	March 31,
	2018			2017
Total segment gross contribution	$	614,814		$	388,617
Costs and expenses:
Cost of services and product development - unallocated (1)	8,458			1,057
Selling, general and administrative	487,745			304,244
Depreciation and amortization	68,056			16,530
Acquisition and integration charges	59,266			13,272
Operating (loss) income	(8,711		)	53,514
Interest expense and other, net	34,160			5,017
(Benefit) provision for income taxes	(23,284		)	12,064
Net (loss) income	$	(19,587	)	$	36,433


(1)	The unallocated amounts consist of certain bonus and related fringe costs recorded in consolidated Cost of services and product development expense that are not allocated to segment expense. The Company's policy is to only allocate bonus and related fringe charges to segments for up to 100% of the segment employee's target bonus. Amounts above 100% are absorbed by corporate.

Goodwill and Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of changes to the carrying amount of goodwill by reporting unit

The following table presents changes to the carrying amount of goodwill by segment during the three months ended March 31, 2018 (in thousands):



	Research			Events			Consulting		Talent Assessment & Other			Total
Balance at December 31, 2017 (1), (2)	$	2,619,677		$	187,920		$	97,798	$	81,899		$	2,987,294
Reclassified as held-for-sale (3)	—			—			—		(20,547		)	(20,547		)
Foreign currency translation impact and other (4)	(17,958		)	(170		)	528		7,495			(10,105		)
Balance at March 31, 2018	$	2,601,719		$	187,750		$	98,326	$	68,847		$	2,956,642


(1)	The Company does not have any accumulated goodwill impairment losses.


(2)	Excludes certain amounts related to held-for-sale operations.


(3)	Represents amounts reclassified as held-for-sale assets related to the CEB Talent Assessment and WS&A businesses. See Note 2 — Acquisitions and Divestitures for additional information.


(4)	Includes the foreign currency translation impact and certain measurement period adjustments related to the acquisition of CEB in April 2017.

Schedule of amortizable intangible assets

The following tables present reconciliations of the carrying amounts of the Company's finite-lived intangible assets as of the dates indicated (in thousands):



March 31, 2018	Customer Relationships			Software			Content			Other			Total
Gross cost at December 31, 2017 (1)	$	1,200,316		$	123,424		$	104,313		$	54,929		$	1,482,982
Write-off of fully amortized intangible assets	—			—			(228		)	—			(228		)
Reclassified as held-for-sale (2)	(7,170		)	(321		)	(241		)	(39		)	(7,771		)
Foreign currency translation impact	15,218			491			251			(171		)	15,789
Gross cost	1,208,364			123,594			104,095			54,719			1,490,772
Accumulated amortization (3)	(119,075		)	(32,410		)	(63,778		)	(27,738		)	(243,001		)
Balance at March 31, 2018 (1)	$	1,089,289		$	91,184		$	40,317		$	26,981		$	1,247,771



December 31, 2017	Customer Relationships			Software			Content			Other			Total
Gross cost (1)	$	1,200,316		$	123,424		$	104,313		$	54,929		$	1,482,982
Accumulated amortization (3)	(92,983		)	(26,344		)	(47,475		)	(24,158		)	(190,960		)
Balance at December 31, 2017 (1)	$	1,107,333		$	97,080		$	56,838		$	30,771		$	1,292,022

(1) Excludes amounts related to held-for-sale operations.


(2)	Represents amounts reclassified (net) as held-for-sale assets related to the WS&A business. See Note 2 — Acquisitions and Divestitures for additional information.

Schedule of estimated future amortization expense by year

The estimated future amortization expense by year for finite-lived intangible assets is as follows (in thousands):



2018 (remaining nine months)	$	138,953
2019	135,868
2020	129,461
2021	108,979
2022	99,363
Thereafter	635,147
	$	1,247,771

Debt (Tables)

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Schedule of debt

The following table summarizes the Company’s total outstanding borrowings as of the dates indicated (in thousands):



	March 31,			December 31,
Description:	2018			2017
2016 Credit Agreement - Term loan A facility (1)	$	1,410,750		$	1,429,312
2016 Credit Agreement - Term loan B facility (1)	495,000			496,250
2016 Credit Agreement - Revolving credit facility (1), (2)	310,000			595,000
Senior Notes (3)	800,000			800,000
Other (4)	2,385			2,500
Principal amount outstanding (5)	$	3,018,135		$	3,323,062
Less: deferred financing fees (6)	(42,350		)	(44,217		)
Net balance sheet carrying amount (7)	$	2,975,785		$	3,278,845

(1)


(2)	The Company had $866.0 million of available borrowing capacity on the revolver (not including the expansion feature) as of March 31, 2018.


(3)	Consists of $800.0 million principal amount of Senior Notes outstanding. The Senior Notes pay a fixed rate of 5.125% and mature on April 1, 2025.


(4)	Consists of a $2.5 million State of Connecticut economic development loan with a 3.00% fixed rate of interest. The loan was originated in 2012 and has a 10 year maturity. Principal payments are deferred for the first five years and the loan may be repaid at any time by the Company without penalty.


(5)	The average annual effective rate on the Company's total debt outstanding for the three months ended March 31, 2018, including the effect of its interest rate swaps discussed below, was 4.14%.


(6)	The deferred financing fees are being amortized to Interest expense, net over the term of the related debt obligation.


(7)	On April 30, 2018, the Company repaid $400.0 million of the Term loan B facility and $50.0 million of the revolving credit facility.

Equity (Tables)

3 Months Ended

Mar. 31, 2018

Stockholders' Equity Note [Abstract]

Schedule of share repurchase activity

The Company’s recent share repurchase activity is presented in the following table:



	Three Months Ended
	March 31,
	2018		2017
Number of shares repurchased (1), (2)	239,268		218,752
Cash paid for repurchased shares (in thousands)	$	28,394	$	21,978

(1) The average purchase price for repurchased shares was $118.73 and $100.47 for the three months ended March 31, 2018 and 2017, respectively.

(2) All of the shares repurchased in both quarterly periods related to the settlement of the Company's share-based compensation awards.

Schedule of the changes in Accumulated Other Comprehensive (Loss) Income by component (net of tax)

For the three months ended March 31, 2018:



	Interest Rate Swaps		Defined Benefit Pension Plans			Foreign Currency Translation Adjustments		Total
Balance – December 31, 2017	$	2,483	$	(5,861	)	$	4,886	$	1,508
Changes during the period:
Change in AOCI/L before reclassifications to income	9,365		—			20,547		29,912
Reclassifications from AOCI/L to income during the period (2), (3)	749		56			—		805
Other comprehensive income for the period	10,114		56			20,547		30,717
Balance – March 31, 2018	$	12,597	$	(5,805	)	$	25,433	$	32,225

For the three months ended March 31, 2017:



	Interest Rate Swaps			Defined Benefit Pension Plans			Foreign Currency Translation Adjustments			Total
Balance – December 31, 2016	$	(1,409	)	$	(5,797	)	$	(42,477	)	$	(49,683	)
Changes during the period:
Change in AOCI/L before reclassifications to income	(3,393		)	—			4,371			978
Reclassifications from AOCI/L to income during the period (2), (3)	825			48			—			873
Other comprehensive income (loss) for the period	(2,568		)	48			4,371			1,851
Balance – March 31, 2017	$	(3,977	)	$	(5,749	)	$	(38,106	)	$	(47,832	)


(1)	Amounts in parentheses represent debits (deferred losses).


(2)	The reclassifications related to interest rate swaps (cash flow hedges) were recorded in Interest expense, net of tax effect. See Note 10 – Derivatives and Hedging for information regarding the hedges.


(3)	The reclassifications related to defined benefit pension plans were recorded in Selling, general and administrative expense, net of tax effect. See Note 12 – Employee Benefits for information regarding the Company’s defined benefit pension plans.

Derivatives and Hedging (Tables)

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of information regarding outstanding derivative contracts

The following tables provide information regarding the Company’s outstanding derivatives contracts as of the dates indicated (in thousands, except for number of outstanding contracts):



March 31, 2018
Derivative Contract Type	Number of Outstanding Contracts	Notional Amounts		Fair Value Asset (Liability), Net (3)			Balance Sheet Line Item	Unrealized Gain Recorded in AOCI/L
Interest rate swaps (1)	5	$	1,400,000	$	17,314		Other assets	$	12,597
Foreign currency forwards (2)	46	313,425		(495		)	Accrued liabilities	—
Total	51	$	1,713,425	$	16,819			$	12,597



December 31, 2017
Derivative Contract Type	Number of Outstanding Contracts	Notional Amounts		Fair Value Asset (Liability), Net (3)		Balance Sheet Line Item	Unrealized Gain Recorded in AOCI/L
Interest rate swaps (1)	5	$	1,400,000	$	3,412	Other assets	$	2,483
Foreign currency forwards (2)	137	686,764		448		Other current assets	—
Total	142	$	2,086,764	$	3,860		$	2,483


(1)	The swaps have been designated and are accounted for as cash flow hedges of the forecasted interest payments on borrowings. As a result, changes in the fair value of the swaps are deferred and recorded in AOCI/L, net of tax effect (see Note 7 — Debt for additional information).

(2)


(3)	See Note 11 — Fair Value Disclosures for the determination of the fair value of these instruments.

Schedule of amounts recognized in statement of operations

The following table provides information regarding amounts recognized in the Condensed Consolidated Statements of Operations for derivative contracts for the periods indicated (in thousands):



	Three Months Ended
	March 31,
Amount recorded in:	2018			2017
Interest expense (1)	$	945		$	1,375
Other (gain) loss, net (2)	(7,232		)	219
Total (income) expense, net	$	(6,287	)	$	1,594


(1)	Consists of interest expense from interest rate swap contracts.


(2)	Consists of net realized and unrealized gains and losses on foreign currency forward contracts.

Fair Value Disclosures (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of assets and liabilities that are remeasured to fair value

The following table presents the fair value of certain financial assets and liabilities (in thousands):



Description:	March 31, 2018		December 31, 2017
Assets:
Values based on Level 1 inputs:
Deferred compensation plan assets (1)	$	16,746	$	29,108
Total Level 1 inputs	16,746		29,108
Values based on Level 2 inputs:
Deferred compensation plan assets (1)	59,477		59,017
Foreign currency forward contracts (2)	156		2,053
Interest rate swap contracts (3)	17,314		3,412
Total Level 2 inputs	76,947		64,482
Total Assets	$	93,693	$	93,590
Liabilities:
Values based on Level 2 inputs:
Deferred compensation plan liabilities (1)	$	73,172	$	89,900
Foreign currency forward contracts (2)	651		1,605
Senior Notes due 2025 (4)	801,640		837,560
Total Level 2 inputs	875,463		929,065
Total Liabilities	$	875,463	$	929,065

(1)


(2)	The Company enters into foreign currency forward exchange contracts to hedge the effects of adverse fluctuations in foreign currency exchange rates (see Note 10 - Derivatives and Hedging). Valuation of the foreign currency forward contracts is based on observable foreign currency exchange rates in active markets, which the Company considers a Level 2 input.

(3)


(4)	As discussed in Note 7 — Debt, the Company has $800.0 million of principal amount fixed-rate Senior Notes due in 2025. The estimated fair value of the notes was derived from quoted market prices provided by an independent dealer which the Company considers to be a Level 2 input.

Business and Basis of Presentation - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) segment country employee	Mar. 31, 2017 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of organizations Company serves \| employee	15,000
Number of countries in which entity operates \| country	100
Number of reportable segments \| segment	4
Segment Reporting Information [Line Items]
Cash used in investing activities	$ 16,679	$ 121,865
Cash and cash equivalents and restricted cash	$ 227,630	$ 1,271,162		$ 567,058	$ 499,354
Percent of subscription contracts billable upon signing for twelve months of service	65.00%
Restatement Adjustment \| Accounting Standards Update 2016-18
Segment Reporting Information [Line Items]
Cash used in investing activities	$ 18,200
Cash and cash equivalents and restricted cash	$ 43,300			$ 25,100
Retained Earnings \| Accounting Standards Update 2016-16
Segment Reporting Information [Line Items]
Cumulative effect of new accounting principle in period of adoption			$ 13,700
Revenue \| Research \| Product Concentration Risk
Segment Reporting Information [Line Items]
Percentage of segment revenues derived from subscription contracts	90.00%

Business and Basis of Presentation - Schedule of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 189,979	$ 538,908	$ 1,227,891	$ 474,233
Restricted cash classified in:
Prepaid expenses and other current assets	18,143	15,148	25,121	25,121
Other assets	0	3,002	18,150	0
Cash and cash equivalents	19,508	10,000	0	0
Cash and cash equivalents and restricted cash	$ 227,630	$ 567,058	$ 1,271,162	$ 499,354

Business and Basis of Presentation - Impact of Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fees receivable	$ (1,134,964)		$ (1,176,843)
Prepaid expenses and other current assets	175,204		124,632
Allowance for doubtful accounts	(7,100)		(12,700)
Accounts payable and accrued liabilities	$ 532,538		$ 666,821
Accounting Standards Update 2014-09 \| Difference between Revenue Guidance in Effect before and after Topic 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fees receivable		$ 26,700
Prepaid expenses and other current assets		26,700
Allowance for doubtful accounts		6,200
Accounts payable and accrued liabilities		$ 6,200

Business and Basis of Presentation - Disaggregation of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	$ 963,565	$ 625,169
Research
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	763,924	511,306
Events
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	46,087	35,269
Consulting
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	82,896	78,594
Talent Assessment & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	70,658	0
United States and Canada
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	593,505	392,987
United States and Canada \| Research
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	489,713	327,492
United States and Canada \| Events
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	24,069	17,663
United States and Canada \| Consulting
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	45,129	47,832
United States and Canada \| Talent Assessment & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	34,594	0
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	259,666	153,720
Europe, Middle East and Africa \| Research
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	184,547	115,802
Europe, Middle East and Africa \| Events
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	16,891	14,095
Europe, Middle East and Africa \| Consulting
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	29,938	23,823
Europe, Middle East and Africa \| Talent Assessment & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	28,290	0
Other International
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	110,394	78,462
Other International \| Research
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	89,664	68,012
Other International \| Events
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	5,127	3,511
Other International \| Consulting
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	7,829	6,939
Other International \| Talent Assessment & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	$ 7,774	$ 0

Business and Basis of Presentation - Timing Of Revenue Recognition Liabilities per Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	$ 963,565	$ 625,169
Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	834,052	531,700
Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	129,513	93,469
Research
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	763,924	511,306
Research \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	701,096	466,706
Research \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	62,828	44,600
Events
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	46,087	35,269
Events \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	0	0
Events \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	46,087	35,269
Consulting
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	82,896	78,594
Consulting \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	74,010	64,994
Consulting \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	8,886	13,600
Talent Assessment & Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	70,658	0
Talent Assessment & Other \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	58,946	0
Talent Assessment & Other \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customer	$ 11,712	$ 0

Business and Basis of Presentation - Revenue Remaining Performance Obligation (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 1,060.6
Revenue, remaining performance obligation, expected timing of satisfaction period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 856.7
Revenue, remaining performance obligation, expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,100.0
Revenue, remaining performance obligation, expected timing of satisfaction period

Business and Basis of Presentation - Schedule of Contract with Customer, Asset and Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Assets:
Fees receivable, gross	$ 1,142,064		$ 1,162,871
Contract assets	27,593		26,672
Contract liabilities:
Deferred revenues (current liability)	1,719,637		1,630,198
Non-current deferred revenues	16,139		16,205
Total contract liabilities	1,735,776		$ 1,646,403
Revenue recognized previously attributable to deferred revenues	605,500
Revenue reserve balance	$ 6,900
Amortization of deferred sales commissions, amortization period	1 year
Amortization of deferred sales commissions	$ 75,900	$ 50,200

Acquisitions and Divestitures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Apr. 30, 2018	Apr. 03, 2018
Business Acquisition [Line Items]
Acquisition and integration charges	$ 59,266	$ 13,272
Talent Assessment \| Disposal Group, Held-for-sale, Not Discontinued Operations
Business Acquisition [Line Items]
Disposal group, revenue	47,000
Disposal group, pre-tax income	$ 2,100
Subsequent Event \| Talent Assessment \| Disposal Group, Held-for-sale, Not Discontinued Operations
Business Acquisition [Line Items]
Disposal group, consideration received				$ 400,000
Subsequent Event \| Workforce Surveys & Analytics \| Disposal Group, Held-for-sale, Not Discontinued Operations
Business Acquisition [Line Items]
Disposal group, consideration received			$ 29,000

- Definition

Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

+ References + Details

Acquisitions and Divestitures - Summary of Exited Space Liability (Details) - CEB	3 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)
Liability Related to Exited Space [Roll Forward]
Beginning liability balance	$ 12,961
Charges and adjustments, net	44,230,000	$ 57,300,000
Payments	(4,734,000)	(4,900,000)
Ending liability balance	52,457,000	52,457,000
Total anticipated exit costs	$ 61,200,000	$ 61,200,000

Acquisitions and Divestitures - Disposals (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 19,508	$ 10,000	$ 0	$ 0
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	19,508	10,000
Fees receivable, net	49,191	50,928
Goodwill	246,661	212,994
Intangible assets, net	264,145	250,472
Other assets	23,849	18,571
Total assets held-for-sale	603,354	542,965
Accounts payable and accrued liabilities	26,467	32,388
Deferred revenues	65,846	61,450
Other liabilities	51,644	52,007
Total liabilities held-for-sale	$ 143,957	$ 145,845

Computation of Net (Loss) Income per Share - Calculations Of Basic And Diluted (Loss) Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net (loss) income used for calculating basic and diluted (loss) income per common share	$ (19,587)	$ 36,433
Denominator:
Weighted average number of common shares used in the calculation of basic (loss) income per share (in shares)	91,005	82,835
Common stock equivalents associated with stock-based compensation plans (in shares)	0	1,260
Shares used in the calculation of diluted (loss) income per share (in shares)	91,005	84,095
Basic (loss) income per share (in dollars per share)	$ (0.22)	$ 0.44
Diluted (loss) income per share (in dollars per share)	$ (0.22)	$ 0.43

Computation of Net (Loss) Income per Share (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of (loss) income per share (less than) (in shares)	1.3	0.4

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)	4.9
Common stock par value (in dollars per share)	$ 0.0005		$ 0.0005
Total share-based compensation cost not yet recognized	$ 125,800,000
Total compensation cost not yet recognized, period for recognition	2 years 10 months 24 days
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan, stock purchases as percentage of employee compensation maximum	10.00%
Maximum share value authorized for purchase under employee stock purchase plan	$ 23,750
Exercisable price percentage of closing price of another class of stock	95.00%
Maximum number of shares that may be purchased by eligible participants (in shares)	0.8
Proceeds from stock plans	$ 4,100,000	$ 3,000,000

Stock-Based Compensation - Stock-based Compensation Expense by Award Type and Expense Category (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 30.9	$ 22.6
Cost of services and product development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	11.4	9.3
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	18.2	13.3
Acquisition and integration charges
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1.3	0.0
Stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	3.5	2.8
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	27.2	19.6
Common stock equivalents
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	0.2	0.2
Retirement eligible employees equity award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 17.8	$ 14.5

Stock-Based Compensation - Summary Of Changes In SARs Outstanding (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation cost not yet recognized, period for recognition	2 years 10 months 24 days
Stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Award expiration period from date of grant	7 years
Total compensation cost not yet recognized, period for recognition	4 years
SARs [Roll Forward]
Outstanding at December 31, 2017 (in shares)	1.2
Granted (in shares)	0.3
Outstanding at March 31, 2018 (in shares)	1.5	1.2
Vested and exercisable at March 31, 2018 (in shares)	0.8
Aggregate Intrinsic value of outstanding shares	$ 47.6
Aggregate intrinsic value of shares vested and exercisable	$ 35.1
Per Share Weighted Average Exercise Price [Roll Forward]
Outstanding at December 31, 2017 (in dollars per share)	$ 76.73
Granted (in dollars per share)	114.26
Outstanding at March 31, 2018 (in dollars per share)	85.06	$ 76.73
Vested and exercisable at March 31, 2018 (in dollars per share)	70.96
Per Share Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at December 31, 2017 (in dollars per share)	17.35
Granted (in dollars per share)	25.63
Outstanding at March 31, 2018 (in dollars per share)	19.15	$ 17.35
Vested and exercisable at March 31, 2018 (in dollars per share)	$ 16.39
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Remaining Contractual Term [Abstract]
Granted	6 years 10 months 10 days
Outstanding weighted average remaining contractual term	4 years 8 months 12 days	4 years 3 months 12 days
Vested and exercisable at March 31, 2018	3 years 6 months 22 days
Unvested \| Stock appreciation rights
SARs [Roll Forward]
Outstanding at March 31, 2018 (in shares)	0.7

Stock-Based Compensation - Weighted Average Assumptions Used To Determine Fair Value Of SARs Grants On Date Of Grant Using Black-Scholes (Details) - Stock appreciation rights	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield	0.00%	0.00%
Expected stock price volatility	21.00%	22.00%
Risk-free interest rate	2.50%	1.80%
Expected life in years	4 years 6 months	4 years 6 months

Stock-Based Compensation - Summary Of Changes In RSUs Outstanding (Details) shares in Millions	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Restricted Stock Units (RSUs) [Roll Forward]
Outstanding at December 31, 2017 (in shares)	1.5
Granted (in shares)	0.7
Vested and released (in shares)	(0.6)
Outstanding at March 31, 2018 (in shares)	1.6
Per Share Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at December 31, 2017 (in dollars per share) \| $ / shares	$ 91.47
Granted (in dollars per share) \| $ / shares	114.33
Vested and released (in dollars per share) \| $ / shares	86.21
Outstanding at March 31, 2018 (in dollars per share) \| $ / shares	$ 101.52
Weighted average remaining contractual terms	1 year 9 months 18 days
Restricted stock units \| Executive officer
Restricted Stock Units (RSUs) [Roll Forward]
Granted (in shares)	0.3
Restricted stock units \| Executive officer \| Minimum \| Target amount
Per Share Weighted Average Grant Date Fair Value [Roll Forward]
Percentage of shares authorized for grant	0.00%
Restricted stock units \| Executive officer \| Maximum \| Target amount
Per Share Weighted Average Grant Date Fair Value [Roll Forward]
Percentage of shares authorized for grant	200.00%
Restricted stock units \| Non executive
Restricted Stock Units (RSUs) [Roll Forward]
Granted (in shares)	0.4
Performance-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Performance-based RSUs \| Executive officer
Restricted Stock Units (RSUs) [Roll Forward]
Granted (in shares)	0.2

Stock-Based Compensation - Summary Of Changes In CSEs Outstanding (Details) - Common stock equivalents	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Base fee percentage (up to)	50.00%
Common Stock Equivalents (CSEs) [Roll Forward]
Outstanding at December 31, 2017 (in shares) \| shares	110,013
Granted (in shares) \| shares	1,624
Converted to common shares upon grant (in shares) \| shares	(998)
Outstanding at March 31, 2018 (in shares) \| shares	110,639
Per Share Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding at December 31, 2017 (in dollars per share) \| $ / shares	$ 23.19
Granted (in dollars per share) \| $ / shares	116.06
Converted to common shares upon grant (in dollars per share) \| $ / shares	124.94
Outstanding at March 31, 2018 (in dollars per share) \| $ / shares	$ 23.59

Segment Information - Information About Reportable Segments (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments \| segment	4
Number of reportable segments \| segment	4
Revenues	$ 963,565,000	$ 625,169,000
Operating (loss) income	(8,711,000)	53,514,000
Intersegment revenues
Segment Reporting Information [Line Items]
Revenues	0	0
Reportable segments
Segment Reporting Information [Line Items]
Revenues	963,565,000	625,169,000
Gross contribution	614,814,000	388,617,000
Corporate and other expenses
Segment Reporting Information [Line Items]
Corporate and other expenses	(623,525,000)	(335,103,000)
Research
Segment Reporting Information [Line Items]
Revenues		6,700,000
Gross contribution		4,400,000
Research \| Reportable segments
Segment Reporting Information [Line Items]
Revenues	763,924,000	511,306,000
Gross contribution	531,456,000	351,113,000
Events \| Reportable segments
Segment Reporting Information [Line Items]
Revenues	46,087,000	35,269,000
Gross contribution	16,190,000	13,567,000
Consulting
Segment Reporting Information [Line Items]
Revenues		(6,700,000)
Gross contribution		(4,400,000)
Consulting \| Reportable segments
Segment Reporting Information [Line Items]
Revenues	82,896,000	78,594,000
Gross contribution	24,124,000	23,937,000
Talent Assessment & Other \| Reportable segments
Segment Reporting Information [Line Items]
Revenues	70,658,000	0
Gross contribution	$ 43,044,000	$ 0

Segment Information - Reconciliation of Segment Gross Contribution to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Costs and expenses:
Cost of services and product development - unallocated	$ 357,209	$ 237,609
Selling, general and administrative	487,745	304,244
Acquisition and integration charges	59,266	13,272
Operating (loss) income	(8,711)	53,514
Interest expense and other, net	34,160	5,017
(Benefit) provision for income taxes	(23,284)	12,064
Net (loss) income	(19,587)	36,433
Reportable segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment gross contribution	$ 614,814	388,617
Reportable segments \| Maximum
Costs and expenses:
Percent of target bonus allocated to segments	100.00%
Corporate and other expenses
Costs and expenses:
Cost of services and product development - unallocated	$ 8,458	1,057
Selling, general and administrative	487,745	304,244
Depreciation and amortization	68,056	16,530
Acquisition and integration charges	$ 59,266	$ 13,272

Goodwill and Intangible Assets - Changes to Carrying Amount of Goodwill by Reporting Unit (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Sep. 30, 2017	Dec. 31, 2017
Goodwill [Line Items]
Goodwill impairment		$ 0
Goodwill, accumulated impairment losses			$ 0
Goodwill [Roll Forward]
Balance, December 31, 2017	$ 2,987,294,000
Reclassified as held-for-sale	(20,547,000)
Foreign currency translation impact and other	(10,105,000)
Balance at March 31, 2018	2,956,642,000
Research
Goodwill [Roll Forward]
Balance, December 31, 2017	2,619,677,000
Reclassified as held-for-sale	0
Foreign currency translation impact and other	(17,958,000)
Balance at March 31, 2018	2,601,719,000
Consulting
Goodwill [Roll Forward]
Balance, December 31, 2017	97,798,000
Reclassified as held-for-sale	0
Foreign currency translation impact and other	528,000
Balance at March 31, 2018	98,326,000
Events
Goodwill [Roll Forward]
Balance, December 31, 2017	187,920,000
Reclassified as held-for-sale	0
Foreign currency translation impact and other	(170,000)
Balance at March 31, 2018	187,750,000
Talent Assessment & Other
Goodwill [Roll Forward]
Balance, December 31, 2017	81,899,000
Reclassified as held-for-sale	(20,547,000)
Foreign currency translation impact and other	7,495,000
Balance at March 31, 2018	$ 68,847,000

Goodwill and Intangible Assets - Carrying Amounts of Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 1,482,982
Write-off of fully amortized intangible assets	(228)
Reclassified as held-for-sale	7,771
Foreign currency translation impact	15,789
Gross cost, ending balance	1,490,772
Accumulated amortization	(243,001)		$ (190,960)
Finite-lived intangible assets, net	1,247,771		1,292,022
Amortization of intangibles	51,646	$ 6,290
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	1,200,316
Write-off of fully amortized intangible assets	0
Reclassified as held-for-sale	7,170
Foreign currency translation impact	15,218
Gross cost, ending balance	1,208,364
Accumulated amortization	(119,075)		(92,983)
Finite-lived intangible assets, net	$ 1,089,289		1,107,333
Customer Relationships \| Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	4 years
Customer Relationships \| Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	13 years
Software
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 123,424
Write-off of fully amortized intangible assets	0
Reclassified as held-for-sale	321
Foreign currency translation impact	491
Gross cost, ending balance	123,594
Accumulated amortization	(32,410)		(26,344)
Finite-lived intangible assets, net	$ 91,184		97,080
Software \| Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	3 years
Software \| Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	7 years
Content
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 104,313
Write-off of fully amortized intangible assets	(228)
Reclassified as held-for-sale	241
Foreign currency translation impact	251
Gross cost, ending balance	104,095
Accumulated amortization	(63,778)		(47,475)
Finite-lived intangible assets, net	$ 40,317		56,838
Content \| Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	1 year 6 months
Content \| Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	5 years
Other
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 54,929
Write-off of fully amortized intangible assets	0
Reclassified as held-for-sale	39
Foreign currency translation impact	(171)
Gross cost, ending balance	54,719
Accumulated amortization	(27,738)		(24,158)
Finite-lived intangible assets, net	$ 26,981		$ 30,771
Other \| Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	2 years
Other \| Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	5 years

Goodwill and Intangible Assets - Estimated Future Amortization Expense By Year From Amortizable Intangibles (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2018 (remaining nine months)	$ 138,953
2019	135,868
2020	129,461
2021	108,979
2022	99,363
Thereafter	635,147
Finite-lived intangible assets, net	$ 1,247,771	$ 1,292,022

Debt (Details)	3 Months Ended
Debt (Details)	Mar. 31, 2018 USD ($) installment payment
Interest rate swaps
Debt Instrument [Line Items]
Derivative, term of contract	30 days
Interest rate, fair value hedge derivative at fair value, net	$ 17,300,000
Senior Notes
Debt Instrument [Line Items]
Proceeds from issuance of debt	$ 800,000,000
Debt instrument, fixed interest rate	5.125%
Debt instrument, issue price, percent	100.00%
Debt instrument, redemption, prince, percentage of principal amount that may be redeemed	40.00%
Senior Notes \| Debt instrument, redemption with the proceeds of certain equity offerings
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage	105.125%
Senior Notes \| Debt instrument, redemption excluding make whole premium
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage	100.00%
Senior Notes \| Debt instrument, redemption due to specific kinds of change of control
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage	101.00%
2016 Agreement
Debt Instrument [Line Items]
Debt instrument, interest, additional interest above eurodollar rate	1.00%
2016 Agreement \| Federal Funds Rate
Debt Instrument [Line Items]
Debt instrument interest additional interest above federal fund rate	0.50%
Minimum applicable margin rate	0.125%
Maximum applicable margin rate	1.50%
2016 Agreement \| Euro Dollar rate
Debt Instrument [Line Items]
Minimum applicable margin rate	1.125%
Maximum applicable margin rate	2.50%
2016 Agreement \| Term loans \| Bank Term Loan - A Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,500,000,000.0
2016 Agreement \| Term loans \| Bank Term Loan - B Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	500,000,000
2016 Agreement \| Revolving credit facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,200,000,000.0
Bank Term Loan - A Facility \| Term loans
Debt Instrument [Line Items]
Line of credit facility, frequency of payments, number of quarterly installments \| installment	16
Bank Term Loan - B Facility \| Term loans \| LIBOR
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%
Bank Term Loan - B Facility \| Term loans \| Base Rate
Debt Instrument [Line Items]
Line of credit facility, frequency of payments, number of quarterly installments \| payment	28
Debt instrument, basis spread on variable rate	1.00%

Debt - Borrowings (Details) - USD ($)		3 Months Ended		12 Months Ended
Debt - Borrowings (Details) - USD ($)	Apr. 30, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2012	Dec. 31, 2017
Debt Instrument [Line Items]
Principal amount outstanding		$ 3,018,135,000			$ 3,323,062,000
Less: deferred financing fees		(42,350,000)			(44,217,000)
Net balance sheet carrying amount		$ 2,975,785,000			3,278,845,000
Average annual effective rate		4.14%
Repayments of debt		$ 304,813,000	$ 0
Subsequent Event
Debt Instrument [Line Items]
Repayments of debt	$ 450,000,000
Revolving credit facility
Debt Instrument [Line Items]
Long-term debt, gross		$ 310,000,000			595,000,000
Contractual annualized interest rate		4.38%
Floating eurodollar base rate		1.88%
Debt instrument interest additional interest above base rate		2.50%
Line of credit facility, remaining borrowing capacity		$ 866,000,000
Revolving credit facility \| Subsequent Event
Debt Instrument [Line Items]
Repayments of debt	50,000,000
Bank Term Loan - A Facility
Debt Instrument [Line Items]
Long-term debt, gross		$ 1,410,750,000			1,429,312,000
Contractual annualized interest rate		3.88%
Floating eurodollar base rate		1.88%
Debt instrument interest additional interest above base rate		2.00%
Bank Term Loan - B Facility
Debt Instrument [Line Items]
Long-term debt, gross		$ 495,000,000			496,250,000
Contractual annualized interest rate		3.23%
Floating eurodollar base rate		1.23%
Debt instrument interest additional interest above base rate		2.00%
Bank Term Loan - B Facility \| Subsequent Event
Debt Instrument [Line Items]
Repayments of debt	$ 400,000,000
Senior Notes
Debt Instrument [Line Items]
Long-term debt, gross		$ 800,000,000			800,000,000
Debt instrument, fixed interest rate		5.125%
Connecticut Economic Development Program
Debt Instrument [Line Items]
Long-term debt, gross		$ 2,385,000		$ 2,500,000.0	$ 2,500,000
Debt instrument term				10 years
Debt instrument, fixed interest rate				3.00%
Debt instrument, period principal payments are deferred				5 years

Equity - Share Repurchase Program and Share Repurchase Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Class of Stock [Line Items]
Stock repurchase program, authorized amount	$ 1,200,000,000.0
Stock repurchase program, remaining authorized repurchase amount	$ 1,100,000,000
Number of shares repurchased (in shares)	239,268	218,752
Cash paid for repurchased shares (in thousands)	$ 28,394,000	$ 21,978,000
Treasury stock, average price paid per share (in dollars per share)	$ 118.73	$ 100.47

Equity - Changes in AOCI/L by Component (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 983,465
Other comprehensive income, net of tax	30,717	$ 1,851
Ending balance	987,571
Interest Rate Swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	2,483	(1,409)
Change in AOCI/L before reclassifications to income	9,365	(3,393)
Reclassifications from AOCL/I to income during the period	749	825
Other comprehensive income, net of tax	10,114	(2,568)
Ending balance	12,597	(3,977)
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5,861)	(5,797)
Change in AOCI/L before reclassifications to income	0	0
Reclassifications from AOCL/I to income during the period	56	48
Other comprehensive income, net of tax	56	48
Ending balance	(5,805)	(5,749)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	4,886	(42,477)
Change in AOCI/L before reclassifications to income	20,547	4,371
Reclassifications from AOCL/I to income during the period	0	0
Other comprehensive income, net of tax	20,547	4,371
Ending balance	25,433	(38,106)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1,508	(49,683)
Change in AOCI/L before reclassifications to income	29,912	978
Reclassifications from AOCL/I to income during the period	805	873
Other comprehensive income, net of tax	30,717	1,851
Ending balance	$ 32,225	$ (47,832)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
(Benefit) provision for income taxes	$ (23,284)	$ 12,064
(Loss) income before income taxes	$ (42,871)	$ 48,497
Effective income tax rate	54.30%	24.90%
Tax Cuts and Jobs Act of 2017, incomplete accounting, provisional income tax benefit			$ 123,200
Tax Cuts and Jobs Act of 2017, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense			63,600
Unrecognized tax benefits	$ 63,200		$ 60,300
Decrease in unrecognized tax benefits is reasonably possible	$ 8,000

Derivatives and Hedging - Outstanding Derivatives Contracts (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($) outstanding_contract	Dec. 31, 2017 USD ($) outstanding_contract
Derivatives, Fair Value [Line Items]
Number of Outstanding Contracts \| outstanding_contract	51	142
Notional Amounts	$ 1,713,425	$ 2,086,764
Fair Value Asset (Liability), Net	16,819	3,860
Unrealized Gain Recorded in AOCI/L	$ 12,597	$ 2,483
Designated as hedging instrument \| Other assets \| Interest rate swaps
Derivatives, Fair Value [Line Items]
Number of Outstanding Contracts \| outstanding_contract	5	5
Notional Amounts	$ 1,400,000	$ 1,400,000
Fair Value Asset (Liability), Net	17,314	3,412
Unrealized Gain Recorded in AOCI/L	$ 12,597	$ 2,483
Not Designated as Hedging Instrument \| Accrued liabilities \| Foreign currency forwards
Derivatives, Fair Value [Line Items]
Number of Outstanding Contracts \| outstanding_contract	46
Notional Amounts	$ 313,425
Fair Value Asset (Liability), Net	(495)
Unrealized Gain Recorded in AOCI/L	$ 0
Not Designated as Hedging Instrument \| Other current assets \| Foreign currency forwards
Derivatives, Fair Value [Line Items]
Number of Outstanding Contracts \| outstanding_contract		137
Notional Amounts		$ 686,764
Fair Value Asset (Liability), Net		448
Unrealized Gain Recorded in AOCI/L		$ 0

Derivatives and Hedging - Amounts Recognized in the Condensed Consolidated Statements of Operations for Derivative Contracts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	$ (6,287)	$ 1,594
Interest expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	945	1,375
Other (gain) loss, net
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	$ (7,232)	$ 219

Fair Value Disclosures - Assets And Liabilities Measured At Fair Value On Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Assets measured at fair value on a recurring basis	$ 93,693	$ 93,590
Fair Value, Inputs, Level 1 \| Deferred compensation plan assets
Assets:
Assets measured at fair value on a recurring basis	16,746	29,108
Fair Value, Inputs, Level 2
Assets:
Assets measured at fair value on a recurring basis	76,947	64,482
Liabilities:
Liabilities measured at fair value on a recurring basis	875,463	929,065
Fair Value, Inputs, Level 2 \| Foreign currency forward contracts
Assets:
Assets measured at fair value on a recurring basis	156	2,053
Liabilities:
Liabilities measured at fair value on a recurring basis	651	1,605
Fair Value, Inputs, Level 2 \| Interest rate swap contracts
Assets:
Assets measured at fair value on a recurring basis	17,314	3,412
Fair Value, Inputs, Level 2 \| Deferred compensation plan assets
Assets:
Assets measured at fair value on a recurring basis	59,477	59,017
Fair Value, Inputs, Level 2 \| Deferred compensation plan liabilities
Liabilities:
Liabilities measured at fair value on a recurring basis	73,172	89,900
Senior Notes
Liabilities:
Long term debt	800,000	800,000
Senior Notes \| Fair Value, Inputs, Level 2 \| Senior notes
Liabilities:
Liabilities measured at fair value on a recurring basis	$ 801,640	$ 837,560

Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended
Employee Benefits (Details) - USD ($) $ in Millions	Mar. 31, 2018	Mar. 31, 2017
Retirement Benefits [Abstract]
Net periodic pension expense	$ 0.7	$ 0.7

Commitments and Contingencies (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Payment obligations under indemnification agreements	$ 0

Subsequent Events - (Details) $ in Thousands		1 Months Ended	3 Months Ended
Subsequent Events - (Details) $ in Thousands	Apr. 30, 2018 USD ($)	Apr. 30, 2018 business	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Subsequent Event [Line Items]
Payments on borrowings			$ 304,813	$ 0
Subsequent Event
Subsequent Event [Line Items]
Number of businesses sold \| business		2
Payments on borrowings	$ 450,000