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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] Dividend declared per common share (in USD per share) Per Share (in USD per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] First Street Technology, Inc First Street Technology, Inc [Member] First Street Technology, Inc Schedule of Changes in Allowance for Credit Losses Financing Receivable, Allowance for Credit Loss [Table Text Block] Common stock, shares issued (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Acquisition-related integration and transaction costs Business Combination Integration Related Costs And Transaction Costs Business combination integration related costs and transaction costs. 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Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Income before provision for income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Commitments and Contingencies (see Note 7) Commitments and Contingencies Gross intangible assets Intangible Asset, Finite-Lived, before Accumulated Amortization Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Goodwill [Roll Forward] Goodwill [Roll Forward] LIABILITIES AND SHAREHOLDERS’ EQUITY (DEFICIT) Liabilities and Equity [Abstract] Intangible Asset, Finite-Lived, Class Intangible Asset, Finite-Lived, Class [Domain] All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Remainder of 2026 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Total Number of Shares Repurchased (in shares) Shares repurchased under stock repurchase programs (in shares) Treasury Stock, Shares, Acquired 2027 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One PEO Name PEO Name Geographical Geographical [Axis] Payment of contingent consideration and deferred purchase price from acquisitions Payment for Contingent Consideration Liability, Financing Activities Concentrations Concentration Risk, Credit Risk, Policy [Policy Text Block] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Other Other America Countries [Member] Other America Countries. Accounts receivable, net of allowances Accounts Receivable, Allowance for Credit Loss [Roll Forward] Common stock repurchased and held in treasury Dollar Value of Shares Repurchased Treasury Stock, Value, Acquired, Cost Method Cash, cash equivalents and restricted cash, beginning of period Cash, cash equivalents and restricted cash, end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Schedule Of Finite Lived Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Accounts payable Increase (Decrease) in Accounts Payable Other accrued liabilities Other Accrued Liabilities, Current Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Base Rate Base Rate [Member] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Additions of contingent consideration Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] 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] INTRODUCTION AND BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Debt Instrument Debt Instrument [Axis] Subsequent Event [Table] Subsequent Event [Table] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Common Stock Outstanding [Table] Common Stock Outstanding [Table] Common Stock Outstanding [Table] 2028 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two Total lease costs Lease, Cost First interest payment date Debt Instruments First Interest Payment Date Debt instruments first interest payment date. Customer Customer [Domain] LEASES Lessee, Operating Leases [Text Block] 2027 Long-Term Debt, Maturity, Year One Long-Term Debt, Type Long-Term Debt, Type [Domain] Basic (in USD per share) Earnings Per Share, Basic Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Repurchase of common stock held in treasury Payments for Repurchase of Common Stock Deferred revenue Opening Closing Contract with Customer, Liability, Current Total current assets Assets, Current Insider Trading Arrangements [Line Items] Common stock issued to Directors and (held in)/released from treasury Treasury Stock Value Issued To Directors Value of common stock issued, but undelivered, to directors. The timing of the delivery of the shares has been deferred until a future date. Long-term debt Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Short-term lease costs Short-Term Lease, Cost Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Schedule of Company's Common Stock Repurchases Made on Open Market Class of Treasury Stock [Table Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Product and Service Product and Service [Axis] 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] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Stock Common Stock [Member] Common Stock Issued Common Stock Issued [Member] Common stock issued. Fair value of contingent consideration Business Combination, Contingent Consideration, Liability Operating lease expenses Operating Lease, Cost Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Schedule Of Introduction And Basis Of Presentation [Table] Schedule Of Introduction And Basis Of Presentation [Table] Schedule Of Introduction And Basis Of Presentation [Table] United Kingdom UNITED KINGDOM Percentage of operating revenues accounted for by major customer Concentration Risk, Percentage Concentration Risk Benchmark Concentration Risk Benchmark [Axis] Foreign exchange translation adjustment Goodwill, Foreign Currency Translation, Gain (Loss) Equity Awards Adjustments Equity Awards Adjustments [Member] Revenue from Contract with Customer, Product and Service Benchmark Revenue from Contract with Customer, Product and Service Benchmark [Member] Total liabilities and shareholders’ equity (deficit) Liabilities and Equity Variable lease costs Variable Lease, Cost Employee Stock Option Share-Based Payment Arrangement, Option [Member] Schedule Of Revenues From External Customers And Long Lived Assets [Table] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Segments Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Tabular List, Table Tabular List [Table Text Block] Other non-current liabilities Increase (Decrease) in Other Noncurrent Liabilities Other expense (income) Other Nonoperating Income (Expense) 2029 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three Remainder of 2026 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Remainder of Fiscal Year Name Awards Close in Time to MNPI Disclosures, Individual Name Income tax effect Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent Earnings per common share: Net Income Loss Per Share [Abstract] Net Income Loss Per Share 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] General and administrative General and Administrative Expense Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock (par value $0.01; 100.0 shares authorized; no shares issued) Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Share Repurchase Program Share Repurchase Program [Axis] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Prepaid income taxes Prepaid Taxes Credit Facility Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Interest payment frequency Debt Instrument, Frequency of Periodic Payment Name Measure Name INCOME TAXES Income Tax Disclosure [Text Block] Discrete tax benefit from legal entity restructuring Effective Income Tax Rate Reconciliation, Internal Legal Entity Restructuring, Amount Effective Income Tax Rate Reconciliation, Internal Legal Entity Restructuring, Amount Accounts payable Accounts Payable, Current Pay vs Performance Disclosure [Line Items] All Other - Private Assets Other Operating Segment [Member] Other adjustments Other Noncash Income (Expense) 5.250% senior unsecured notes due 2035 Five Point Two Five Zero Percent Senior Unsecured Notes Due Two Thousand Thirty Five [Member] Five Point Two Five Zero Percent Senior Unsecured Notes Due Two Thousand Thirty Five Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Aggregate purchase price Business Combination, Consideration Transferred Additional Paid in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Blackrock Inc Blackrock Inc [Member] BlackRock Inc. Thereafter Long-Term Debt, Maturity, After Year Four Long-Term Debt, Maturity, After Year Four Name Trading Arrangement, Individual Name Cash and cash equivalents (includes restricted cash of $3.6 and $3.7 at September 30, 2026 and December 31, 2025, respectively) Cash and Cash Equivalent Concentration Risk Benchmark Concentration Risk Benchmark [Domain] Capitalized software development costs Payments for Software Company Selected Measure Amount Company Selected Measure Amount Depreciation and amortization of property, equipment and leasehold improvements Depreciation, Depletion and Amortization Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Increase/(decrease) Increase (Decrease) In Contract With Customer, Liability, Current Increase (decrease) in contract with customer liability, current. Entity Address, Address Line Two Entity Address, Address Line Two Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Current assets: Assets, Current [Abstract] Weighted-average remaining lease term (years) Operating Lease, Weighted Average Remaining Lease Term Non-PEO NEO Non-PEO NEO [Member] Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Right of use assets obtained for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Provision for income taxes Income Tax Expense (Benefit) Customer Concentration Risk Customer Concentration Risk [Member] Award Timing Method Award Timing Method [Text Block] Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Business combination, contingent consideration, range of outcomes, maximum, amount Business Combination, Contingent Consideration, Range of Outcomes, Maximum, Amount RECENT ACCOUNTING PRONOUNCEMENTS Accounting Standards Update and Change in Accounting Principle [Text Block] Net income Net income Net income Net Income (Loss) Attributable to Parent Long-Term Debt, Type Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Balance Sheet Location Location, Statement of Financial Position, Balance [Axis] Statement [Table] Statement [Table] Restatement Determination Date: Restatement Determination Date [Axis] Proceeds from exercise of stock options Proceeds from Stock Options Exercised 3.625% senior unsecured notes due 2030 Three Point Six Two Five Percent Senior Unsecured Notes Due Two Thousand Thirty [Member] Three point six two five percent senior unsecured notes due two thousand thirty. Schedule of Remaining Performance Obligations Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Interest income Investment Income, Interest Schedule of Change in Accounts Receivable and Current Deferred Revenue Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Japan JAPAN Asset-based fees Asset Based Fees [Member] Asset-based fees. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block]