Adjustments to reconcile net income to cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Statistical Measurement [Domain] Statistical Measurement [Domain] Payments on long-term debt Repayments of Long-Term Debt Stock repurchase program, remaining authorized repurchase amount Share Repurchase Program, Remaining Authorized, Amount Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Lease Costs Lease, Cost [Table Text Block] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Cover page. Cover [Abstract] Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Trading Symbol Trading Symbol Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] All Trading Arrangements All Trading Arrangements [Member] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Cash and Cash Equivalent [Table] Cash and Cash Equivalent [Table] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Non-NEOs Non-NEOs [Member] Schedule Of Basic And Diluted Earnings Per Share Calculations Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Derivative [Line Items] Derivative [Line Items] Fees receivable, allowance Accounts Receivable, Allowance for Credit Loss, Current Schedule Of Stock-based Compensation Expense By Award Type Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Pay vs Performance Disclosure [Line Items] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Fees receivable, net Increase (Decrease) in Accounts Receivable Derivative [Table] Derivative [Table] Loss on release of interest rate swap recognized in AOCI AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax Business and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Fair Value Disclosures Fair Value Disclosures [Text Block] Contractual annualized interest rate Line of Credit Facility, Interest Rate at Period End Award Timing Disclosures [Line Items] Derivative reclassifications Total expense, net Derivative, Gain (Loss) on Derivative, Net Other Performance Measure, Amount Other Performance Measure, Amount 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Three Goodwill [Line Items] Goodwill [Line Items] Leases Lessee, Operating Leases [Text Block] Operating lease cost Operating Lease, Cost Number of shares available for grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Operating lease liabilities Operating lease liabilities Operating Lease, Liability, Noncurrent Segments Segment Reporting, Policy [Policy Text Block] Revenue from Contract with Customer [Abstract] Line of credit facility, additional borrowing capacity Line of Credit Facility, Additional Borrowing Capacity Line of Credit Facility, Additional Borrowing Capacity Deferred revenues Deferred revenues (current liability) Contract with Customer, Liability, Current Other assets Other Assets, Noncurrent Entity Tax Identification Number Entity Tax Identification Number Leases [Abstract] Gross cost, ending balance Finite-Lived Intangible Assets, Gross Schedule of Finite-Lived Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Number of shares repurchased (in shares) Treasury Stock, Shares, Acquired Operating Segments Operating Segments [Member] Selling, general and administrative Selling, General and Administrative Expenses [Member] Cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Treasury Stock Treasury Stock, Common [Member] 2024 Credit Agreement 2024 Credit Agreement [Member] 2024 Credit Agreement Schedule Of The Changes In Accumulated Other Comprehensive Loss By Component (Net Of Tax) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Intersegment Eliminations Intersegment Eliminations [Member] Equity Components [Axis] Equity Components [Axis] Award Timing Method Award Timing Method [Text Block] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] 2022 Acquisition 2022 Acquisition [Member] 2022 Acquisition Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Insider Trading Policies and Procedures [Line Items] Use of estimates Use of Estimates, Policy [Policy Text Block] Total costs and expenses Costs and Expenses Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Adjustment to Compensation, Amount Adjustment to Compensation Amount Compensation Amount Outstanding Recovery Compensation Amount Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Entity Small Business Entity Small Business Company Selected Measure Amount Company Selected Measure Amount Geographical [Axis] Geographical [Axis] Tabular List, Table Tabular List [Table Text Block] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common share repurchases (including excise tax) Stock Repurchased During Period, Value Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Antidilutive securities excluded from computation of (loss) income per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Credit Facility [Domain] Credit Facility [Domain] Cash and cash equivalents and restricted cash, beginning of period Cash and cash equivalents, end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Current assets: Assets, Current [Abstract] Goodwill Beginning balance Ending balance Goodwill Consolidation Items [Axis] Consolidation Items [Axis] Other comprehensive income (loss), net of tax: Other comprehensive income (loss) activity during the period: Other Comprehensive Income (Loss), Net of Tax [Abstract] Stock repurchase program, authorized amount Share Repurchase Program, Authorized, Amount Treasury stock, common shares (in shares) Treasury Stock, Common, Shares Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Product and Service [Domain] Product and Service [Domain] Employee Stock Option Share-Based Payment Arrangement, Option [Member] Foreign currency forwards Foreign currency forward contracts Foreign Exchange Forward [Member] Goodwill [Roll Forward] Goodwill [Roll Forward] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Depreciation Depreciation Other Other Expenses Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Other International Other International [Member] -- None. No documentation exists for this element. -- Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Security Exchange Name Security Exchange Name Additional interest above base rate Debt Instrument, Basis Spread on Variable Rate Award Type [Axis] Award Type [Axis] Foreign currency translation impact Goodwill, Foreign Currency Translation Gain (Loss) Changes in assets and liabilities, net of acquisitions and divestitures: Increase (Decrease) in Operating Capital, Net of Acquisition [Abstract] -- None. No documentation exists for this element. -- Cash and cash equivalents and restricted cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Other Other Long Term Debt [Member] Other Long Term Debt [Member] Property, equipment and leasehold improvements, net Property, Plant and Equipment, Net Total Liabilities Liabilities Personnel expenses Labor and Related Expense Deferred commissions Increase (Decrease) in Deferred Charges Common stock, par value (in dollars per share) Common stock par value (in dollars per share) Common Stock, Par or Stated Value Per Share Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Revolving credit facility Revolving Credit Facility [Member] Expiration Date Trading Arrangement Expiration Date Investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Accounts payable and accrued liabilities Operating Lease, Liability, Current Total Shareholder Return Amount Total Shareholder Return Amount Common stock, shares issued (in shares) Common Stock, Shares, Issued Other current assets Other Assets [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Economic Development Loan 2 Economic Development Loan 2 [Member] Economic Development Loan 2 [Member] Schedule Of Share Repurchase Activity Class of Treasury Stock [Table Text Block] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Cost for subleasing activities Operating Lease, Cost, Subleasing Activities Operating Lease, Cost, Subleasing Activities Unrealized Loss Recorded in AOCL, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Debt Instrument [Line Items] Debt Instrument [Line Items] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Fair Value Asset (Liability), Net Derivative Assets (Liabilities), at Fair Value, Net Europe, Middle East and Africa Europe Middle East Africa [Member] -- None. No documentation exists for this element. -- Weighted average effective rate Long-Term Debt, Weighted Average Interest Rate, over Time Basis of presentation Basis of Accounting, Policy [Policy Text Block] Diluted (in shares) Shares used in the calculation of diluted income per share (in shares) Weighted Average Number of Shares Outstanding, Diluted Other income, net Other Nonoperating Income (Expense) [Member] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] 2025 (remaining nine months) Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] 2028 Notes Senior Notes Due 2028 [Member] Senior Notes Due 2028 Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Total Stockholders’ Equity Beginning balance Ending balance Equity, Attributable to Parent Renewal term (in years) Lessee, Operating Lease, Renewal Term Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Connecticut Economic Development Program Connecticut Economic Development Program [Member] -- None. No documentation exists for this element. -- Balance Sheet Location [Axis] Statement of Financial Position Location, Balance [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Contract liabilities: Contract with Customer, Liability [Abstract] Interest expense, net Interest Expense, Nonoperating Deferred taxes Deferred Income Tax Expense (Benefit) Schedule of Changes to the Carrying Amount of Goodwill by Reporting Unit Schedule of Goodwill [Table Text Block] Research Research Research Segment [Member] -- None. No documentation exists for this element. -- Accrued liabilities Accrued Liabilities Current [Member] -- None. No documentation exists for this element. -- Selling, general and administrative Selling, General and Administrative Expense Other comprehensive income (loss), net of tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Fair Value, Recurring Fair Value, Recurring [Member] Fees receivable, net of allowances of $7,500 and $8,500, respectively Accounts Receivable, after Allowance for Credit Loss, Current Cost of services and product development Cost of Sales [Member] Carrying Amount Long-Term Debt Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Document Fiscal Period Focus Document Fiscal Period Focus All Executive Categories All Executive Categories [Member] Dilutive effect of outstanding awards associated with stock-based compensation plans (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Balance Sheet Location [Domain] Statement of Financial Position Location, Balance [Domain] Debt instrument, issue price, percent Debt Instrument, Issue Price, Percentage Debt Instrument, Issue Price, Percentage Fees receivable, gross Accounts Receivable, before Allowance for Credit Loss, Current 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Two Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Assets Assets [Abstract] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Document Type Document Type Derivative Contract [Domain] Derivative Contract [Domain] Line of credit facility, commitment fee percentage Line of Credit Facility, Commitment Fee Percentage Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Schedule of Segment Reporting Information by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Schedule for Contract with Customer, Asset and Liability Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Schedule of Estimated Future Amortization Expense by Year Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Maximum Maximum [Member] Amortization of intangibles Amortization of Intangible Assets Total contract liabilities Contract with Customer, Liability Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Goodwill, accumulated impairment losses Goodwill, Impaired, Accumulated Impairment Loss Payments of deferred financing fees Payments of Financing Costs Finite-lived intangible assets, net Finite-Lived Intangible Assets, Net Deferred consideration Business Combination, Deferred Consideration Business Combination, Deferred Consideration Revenues: Revenues [Abstract] Leasehold Improvements Leasehold Improvements [Member] Variable Rate Component One Variable Rate Component One [Member] Variable Rate Component One Current Fiscal Year End Date Current Fiscal Year End Date Total lease cost, net Lease, Cost Statistical Measurement [Axis] Statistical Measurement [Axis] PEO Name PEO Name Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Income before income taxes Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Award Type [Domain] Award Type [Domain] Name Outstanding Recovery, Individual Name Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Lease cost Variable Lease, Cost Goodwill impairment Goodwill, Impairment Loss Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] 2029 Notes Senior Notes Due 2029 [Member] Senior Notes Due 2029 Transferred over time Transferred over Time [Member] Non-PEO NEO Non-PEO NEO [Member] Remaining amortization period Finite-Lived Intangible Asset, Useful Life Net increase (decrease) in cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Additional Paid-In Capital Additional Paid-in Capital [Member] Award Timing Predetermined Award Timing Predetermined [Flag] Customer Relationships Customer Relationships [Member] Adoption of new accounting standard New Accounting Pronouncements, Policy [Policy Text Block] Diluted (in dollars per share) Diluted income per share (in dollars per share) Earnings Per Share, Diluted Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Revenue recognition Revenue from Contract with Customer [Policy Text Block] Name Measure Name Entity Interactive Data Current Entity Interactive Data Current Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Percentage of principal amount redeemed Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Schedule of Assets and Liabilities Measured to Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Research Research Revenue [Member] Research Revenue Defined Benefit Pension Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Gain on de-designated swaps Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Stock repurchase program, additional authorized amount Stock Repurchase Program, Additional Authorized Amount Stock Repurchase Program, Additional Authorized Amount Provision for income taxes Income Tax Expense (Benefit) Debt instrument, fixed interest rate Debt Instrument, Interest Rate, Stated Percentage Interest rate swap contracts total notional value Notional Amounts Derivative, Notional Amount Variable Rate Components [Domain] Variable Rate Components [Domain] Variable Rate Components [Domain] Open Market Purchases Open Market Purchases [Member] Open Market Purchases Total revenues Revenue from Contract with Customer, Excluding Assessed Tax Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance Derivative Instruments, Gain (Loss) [Table Text Block] Variable Rate Component Two Variable Rate Component Two [Member] Variable Rate Component Two Additions to property, equipment and leasehold improvements Payments for Capital Improvements Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Number of contracts Number of Contracts Derivative, Number of Instruments Held Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Cash used in investing activities Net Cash Provided by (Used in) Investing Activities Operating income Operating Income (Loss) Number of reportable segments Number of Reportable Segments Total Liabilities and Stockholders’ Equity Liabilities and Equity Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] All Adjustments to Compensation All Adjustments to Compensation [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Additional paid-in capital Additional Paid in Capital Hedging Designation [Axis] Hedging Designation [Axis] Option to terminate, term (in years) Lessee, Operating Lease, Option to Terminate, Term Lessee, Operating Lease, Option to Terminate, Term Loss on impairment of lease related assets Loss on impairment of lease related assets, net Operating Lease, Impairment Loss Derivatives and Hedging Derivative Instruments and Hedging Activities Disclosure [Text Block] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Right-of-use assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Underlying Security Market Price Change Underlying Security Market Price Change, Percent Individual: Individual [Axis] Accumulated Other Comprehensive Loss, Net Total AOCI Attributable to Parent [Member] Revenue, remaining performance obligation, expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Interest Rate Swaps Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Product and Service [Axis] Product and Service [Axis] Entity Address, State or Province Entity Address, State or Province Statement [Line Items] Statement [Line Items] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Product and content delivery expenses Product And Content Delivery Expenses Product And Content Delivery Expenses Variable Rate Components [Axis] Variable Rate Components [Axis] Variable Rate Components Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Types of Financial Instruments [Domain] Financial Instruments [Domain] Sublease income Sublease Income Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Term of contract Derivative, Term of Contract Assets: Contract with Customer, Asset, after Allowance for Credit Loss [Abstract] Fixed interest rate Derivative, Fixed Interest Rate Minimum Minimum [Member] Restatement Determination Date Restatement Determination Date Adoption Date Trading Arrangement Adoption Date Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Non-current deferred revenues recorded in Other liabilities Contract with Customer, Liability, Noncurrent Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Segments [Axis] Segments [Axis] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Principal amount outstanding Long-Term Debt, Gross Exercise Price Award Exercise Price Supplemental Balance Sheet Information Assets And Liabilities, Leases [Table Text Block] Assets And Liabilities, Leases [Table Text Block] Computation of Earnings Per Share Earnings Per Share [Text Block] Arrangement Duration Trading Arrangement Duration Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Contract assets recorded in Prepaid expenses and other current assets Contract with Customer, Asset, before Allowance for Credit Loss Leases Lessee, Finance Leases [Text Block] Costs and expenses: Costs and Expenses [Abstract] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Stockholders’ Equity Equity, Attributable to Parent [Abstract] Right-of-use assets Right-of-use Assets [Member] Right-of-use Assets Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Segments [Domain] Segments [Domain] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Debt term Debt Instrument, Term 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Four All Individuals All Individuals [Member] Proceeds from revolving credit facility Proceeds from Lines of Credit PEO PEO [Member] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Fair Value Debt Instrument, Fair Value Disclosure Name Trading Arrangement, Individual Name Other income, net Other Nonoperating Income (Expense) Statement of Stockholders' Equity [Abstract] Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Proceeds from employee stock purchase plan Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Including Option Exercised Treasury stock, at cost, 86,214,938 and 86,222,214 common shares, respectively Treasury Stock, Common, Value Conferences Conferences Conferences [Member] -- None. No documentation exists for this element. -- Cost of services and product development - unallocated Other Cost of Operating Revenue Deferred commissions Other Deferred Costs, Net Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Assets: Assets, Fair Value Disclosure [Abstract] Denominator: Denominator: [Abstract] -- None. No documentation exists for this element. -- Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Local Phone Number Local Phone Number Net balance sheet carrying amount Debt, Long-Term and Short-Term, Combined Amount Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Less: deferred financing fees Debt Issuance Costs, Line of Credit Arrangements, Net Interest expense, net Interest Expense [Member] Other assets Increase (Decrease) in Other Operating Assets PEO Total Compensation Amount PEO Total Compensation Amount Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line [Axis] Income Statement Location [Axis] Statement of Income Location, Balance [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Contingencies Commitments and Contingencies Disclosure [Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Common Stock Common Stock [Member] Measure: Measure [Axis] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Debt Instrument, Redemption, Period One Debt Instrument, Redemption, Period One [Member] Entity Emerging Growth Company Entity Emerging Growth Company Total Liabilities Liabilities, Fair Value Disclosure Segment Reporting [Abstract] Segment Reporting [Abstract] Entity Central Index Key Entity Central Index Key Issuances under stock plans Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Percent of target bonus charges allocated to segments Segment Reporting Information, Percent of Target Bonus Charges Allocated to Segments Segment Reporting Information, Percent of Target Bonus Charges Allocated to Segments Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Foreign Currency Translation Adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Equity Equity [Text Block] Accounts payable and accrued and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Equity Component [Domain] Equity Component [Domain] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Financial Instrument [Axis] Financial Instrument [Axis] Segment Information Segment Reporting Disclosure [Text Block] Class of Treasury Stock [Table] Class of Treasury Stock [Table] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Stock-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Entity Shell Company Entity Shell Company Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code 2030 Notes Senior Notes Due 2030 [Member] Senior Notes Due 2030 Title Trading Arrangement, Individual Title Unsecured Debt Unsecured Debt [Member] Statement [Table] Statement [Table] Measurement Frequency [Domain] Measurement Frequency [Domain] Unrecognized tax benefits Unrecognized Tax Benefits Consolidation Items [Domain] Consolidation Items [Domain] Deferred compensation plan assets Plan Assets [Member] -- None. No documentation exists for this element. -- City Area Code City Area Code Current liabilities: Liabilities, Current [Abstract] Finite-lived Intangible Assets [Roll Forward] Finite-Lived Intangible Assets [Roll Forward] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Level 1 Fair Value, Inputs, Level 1 [Member] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Senior Notes Senior Notes [Member] Remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Purchases of treasury stock Cash paid for repurchased shares Payments for Repurchase of Common Stock Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Long-term debt, net of deferred financing fees Long-Term Debt, Excluding Current Maturities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Other Other Intangible Assets [Member] Income Taxes Income Tax Disclosure [Text Block] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Accumulated earnings Retained Earnings (Accumulated Deficit) Loss to be reclassified within twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within 12 Months Schedule of Debt Schedule of Debt [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] Total operating lease liabilities included in the Condensed Consolidated Balance Sheets Operating Lease, Liability Cash used in financing activities Net Cash Provided by (Used in) Financing Activities Underlying Securities Award Underlying Securities Amount Credit Facility [Axis] Credit Facility [Axis] Amendment Flag Amendment Flag Entity Registrant Name Entity Registrant Name Acquisition of business Payments to Acquire Businesses, Gross Transferred at a point in time Transferred at Point in Time [Member] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Depreciation and amortization Depreciation, Depletion and Amortization Stock appreciation rights Stock Appreciation Rights (SARs) [Member] Gross contribution Gross Profit Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Fair Value as of Grant Date Award Grant Date Fair Value Level 2 Fair Value, Inputs, Level 2 [Member] Debt Debt Disclosure [Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Geographical [Domain] Geographical [Domain] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Aggregate principal amount Debt Instrument, Face Amount Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Intangible assets fully amortized Finite Lived Intangible Assets, Fully Amortized Intangibles Finite Lived Intangible Assets, Fully Amortized Intangibles Entity Address, Postal Zip Code Entity Address, Postal Zip Code Schedule Of Stock-Based Compensation Expense By Expense Category Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Principles of consolidation Consolidation, Policy [Policy Text Block] Consulting Consulting Consulting [Member] -- None. No documentation exists for this element. -- Interest rate swaps Interest rate swap contracts Interest Rate Swap [Member] Restatement Determination Date: Restatement Determination Date [Axis] Title of 12(b) Security Title of 12(b) Security Common stock, $0.0005 par value, 250,000,000 shares authorized; 163,602,067 shares issued for both periods Common Stock, Value, Issued Cash receipts from sublease arrangements Proceeds from Lease Payment, Operating Activity Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Net income per share: Net Income Per Share, Basic And Diluted [Abstract] Net Income Per Share, Basic And Diluted Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Preferred stock, $0.01 par value, 5,000,000 shares authorized; none issued or outstanding Preferred Stock, Value, Issued Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Basic (in dollars per share) Basic income per share (in dollars per share) Earnings Per Share, Basic Cash paid for amounts included in the measurement of operating lease liabilities Operating Lease, Payments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Schedule of Goodwill [Table] Goodwill [Table] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Total current liabilities Liabilities, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Total Assets Assets Treasury stock, average price paid per share (in dollars per share) Treasury Stock Average Price Paid Per Share Treasury Stock Average Price Paid Per Share. 2026 Finite-Lived Intangible Asset, Expected Amortization, Year One Cost of services and product development Cost of Goods and Services Sold Long-term line of credit Long-Term Line of Credit Other liabilities Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Common stock equivalents Common Stock Equivalents [Member] -- None. No documentation exists for this element. -- Gross cost, beginning balance Finite-Lived Intangible Assets, Excluding Foreign Currency Translation, Gross Finite-Lived Intangible Assets, Excluding Foreign Currency Translation, Gross Termination Date Trading Arrangement Termination Date Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Revenues Revenues Stock-Based Compensation Share-Based Payment Arrangement [Text Block] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Schedule of Disaggregation of Revenue by Reportable Segment Revenue from External Customers by Geographic Areas [Table Text Block] Entity Address, City or Town Entity Address, City or Town Deferred compensation plan liabilities Plan Liabilities [Member] -- None. No documentation exists for this element. -- Debt Instrument [Axis] Debt Instrument [Axis] Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Stock-based compensation expense Share-Based Payment Arrangement, Expense Net income Net income Net income used for calculating basic and diluted income per share Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Numerator: Numerator: [Abstract] -- None. No documentation exists for this element. -- Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Business Acquisition [Axis] Business Acquisition [Axis] Schedule of Amortizable Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Entity File Number Entity File Number Liabilities: Liabilities, Fair Value Disclosure [Abstract] Revenue and Related Matters Revenue from Contract with Customer [Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Change in AOCL before reclassifications to income OCI, before Reclassifications, before Tax, Attributable to Parent United States and Canada United States And Canada [Member] -- None. No documentation exists for this element. -- Entity Address, Address Line Two Entity Address, Address Line Two Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Effects of exchange rates on cash and cash equivalents Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Total Assets Assets, Fair Value Disclosure Name Forgone Recovery, Individual Name 2030 Finite-Lived Intangible Asset, Expected Amortization, Year Five Document Period End Date Document Period End Date Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Deferred revenues Increase (Decrease) in Deferred Revenue Insider Trading Arrangements [Line Items] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Other current assets Other Current Assets [Member] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Revenue recognized previously attributable to deferred revenues Contract with Customer, Liability, Revenue Recognized Adjustment to Compensation: Adjustment to Compensation [Axis] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Document Transition Report Document Transition Report Document Quarterly Report Document Quarterly Report Retirement Eligible Employees Equity Award Retirement Eligible Employees Equity Award [Member] -- None. No documentation exists for this element. -- Pension plans – net change in deferred actuarial loss Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Accumulated other comprehensive loss, net Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Current Reporting Status Entity Current Reporting Status Accumulated Earnings Retained Earnings [Member] Acquisition and integration charges Acquisition and integration charges Business Combination, Acquisition and Integration Related Costs Business Combination, Acquisition and Integration Related Costs Amortization and write-off of deferred financing fees Amortization of Debt Issuance Costs Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Interest expenses and other, net Interest And Other Nonoperating Income (Expense) Interest And Other Nonoperating Income (Expense) Basic (in shares) Weighted average number of common shares used in the calculation of basic income per share (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Restricted stock units Restricted Stock Units (RSUs) [Member] Reduction in the carrying amount of operating lease right-of-use assets Operating Lease, Right-Of-Use Asset, Reduction In Carrying Amount Operating Lease, Right-Of-Use Asset, Reduction In Carrying Amount Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Name Awards Close in Time to MNPI Disclosures, Individual Name Foreign currency translation impact Finite-Lived Intangible Assets, Foreign Currency Translation Gain (Loss) Entity Filer Category Entity Filer Category Reclassifications from AOCL to income Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Remaining performance obligation, amount Revenue, Remaining Performance Obligation, Amount Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Report Line [Domain] Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Letter of Credit Letter of Credit [Member] Interest rate swaps – net change in deferred gain or loss Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Company Selected Measure Name Company Selected Measure Name