Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Direct pass-through costs PEO revenues Direct Pass Through Costs P E O Revenues Direct pass-through costs associated with PEO, primarily consisting of payroll wages and payroll taxes. Domestic Tax Authority Income Tax Jurisdiction, Domestic Federal [Member] Schedule of Amounts Recognized in Balance Sheet Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Title of 12(b) Security Title of 12(b) Security Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Subsequent Event Subsequent Event [Member] Contract Liability Change in Contract with Customer, Liability [Roll Forward] Change in Contract with Customer, Liability Adjustment to Compensation, Amount Adjustment to Compensation Amount Performance period (years) Share Based Compensation Arrangement By Share Based Payment Award Performance Period Share Based Compensation Arrangement By Share Based Payment Award Performance Period Financial Instrument [Axis] Financial Instrument [Axis] Summary of Reconciliation of the Beginning and Ending Amounts of Unrecognized Tax Benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Segment Reporting [Abstract] Segment Reporting [Abstract] Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense Intangible Asset, Finite-Lived, and Capitalized Cost, Software to be Sold, Leased, or Marketed, Estimated Amortization Expense [Table Text Block] Schedule of Fair Value, Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Accrued payroll and payroll-related expenses Employee-related Liabilities, Current Line of credit facility potentially available increase in maximum borrowing capacity Line Of Credit Facility Potentially Available Increase In Maximum Borrowing Capacity Line Of Credit Facility Potentially Available Increase In Maximum Borrowing Capacity Funds held for clients Total funds held for clients Funds Held Clients Represents assets that, based upon the Company's intent, are restricted for use solely for the purposes of satisfying the obligations to remit funds relating to the Company’s payroll and payroll tax filing services State and local income taxes, net of federal income tax effect State taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Effect of employee restricted stock shares, weighted average shares (in shares) Effect of Employee Restricted stock Shares On Weighted Average Number of Diluted Shares Outstanding Effect of Employee Restricted stock Shares On Weighted Average Number of Diluted Shares Outstanding Loss contingency accrual Loss Contingency Accrual Notional amount of derivatives terminated Derivative, Notional Amount, Terminated During The Period Derivative, Notional Amount, Terminated During The Period Account Classification [Axis] Account Classification [Axis] Account Classification [Axis] Tax effect Other Comprehensive Income (Loss) before Reclassifications, Tax Number of notes issued Number Of Notes Issued Number Of Notes Issued Deferred: Deferred Federal, State and Local, Tax Expense (Benefit) [Abstract] Total current Current Income Tax Expense (Benefit) Government securities US Treasury and Government [Member] Charged to other accounts SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Other Account Schedule of Weighted Average Fair Value of Restricted Stock Granted Weighted Average Fair Value Of Restricted Stock Granted [Table Text Block] Weighted average fair value of restricted stock granted [Text Block] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Threshold for reinsurance per occurrence (up to) Threshold for Reinsurance per Occurrence Threshold for Reinsurance per Occurrence Excess tax benefit - Stock-based compensation Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-Based Payment Arrangement, Amount Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Effective Income Tax Rate Reconciliation, Percent [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Stock-Based Compensation Plan Stock-Based Compensation Plan [Member] Stock-Based Compensation Plan Asset-backed securities Asset-Backed Securities [Member] Deferred contract costs Deferred Tax Liabilities, Deferred Expense, Other Capitalized Costs Other Deferred Tax Liabilities, Other Leases [Abstract] Workers' Compensation Costs Liability Reserve Estimate, Policy [Policy Text Block] Foreign tax effects Foreign rate differential Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Corporate and municipal bonds Corporate And Municipal Bonds [Member] Corporate and municipal bonds. Total, gross unrealized losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract] Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract] Insurance receivables Loss Contingency, Receivable Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Intangible assets, net Intangible assets, net Intangible Asset, Excluding Goodwill, after Accumulated Amortization Accrued expenses not currently deductible Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals Restricted units outstanding, beginning balance Restricted units outstanding, ending balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Foreign Deferred Foreign Income Tax Expense (Benefit) Retirement Benefits [Abstract] Retirement Benefits [Abstract] Net accretion of discounts and amortization of premiums on available-for-sale securities Accretion (Amortization) of Discounts and Premiums, Investments Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Internal Use Software Software, Internal-Use [Policy Text Block] Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current EMEA EMEA [Member] Other comprehensive income/(loss): Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Global Global [Member] Global [Member] Entity Address, City or Town Entity Address, City or Town Effect of cross-border tax laws Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Percent Restricted units granted Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Software, Internally Developed and Purchased Software, Internally Developed and Purchased [Member] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Disallowed business interest expense carryforward Deferred Tax Assets, Disallowed Business Interest Expense Carryforward Deferred Tax Assets, Disallowed Business Interest Expense Carryforward Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Performance Based Restricted Stock Unit Performance Based Restricted Stock Unit [Member] Performance Based Restricted Stock Unit Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Other comprehensive income/(loss), net of tax Other comprehensive income (loss) Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Unrecognized tax benefits, income tax penalties accrued Unrecognized Tax Benefits, Income Tax Penalties Accrued Tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Percent United States UNITED STATES Subsequent Event Type [Axis] Subsequent Event Type [Axis] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Impairment of Long-Lived Assets Long-Lived Asset, Excluding Intangible Asset and Goodwill, Impairment and Disposal [Policy Text Block] Capitalized Contract Cost [Domain] Capitalized Contract Cost [Domain] Other comprehensive (loss)/income before reclassification adjustments OCI, before Reclassifications, before Tax, Attributable to Parent Schedule of Segment Reporting Information, by Segment Segment Reporting [Table Text Block] Municipal Bonds Municipal Bonds [Member] Net (repurchases)/proceeds from stock-based compensation plans and stock purchase plan (Payments For)/ Proceeds From Stock Based Compensation Plans And Stock Purchase Plan, Net (Payments For)/ Proceeds From Stock Based Compensation Plans And Stock Purchase Plan, Net Revenue Recognition and Deferred Costs Revenue from Contract with Customer [Policy Text Block] Schedule of Reconciliation Between Federal Statutory Tax and Effective Tax Rate Reconciliation Between Federal Statutory Tax And Effective Tax Rate [Table Text Block] Reconciliation Between Federal Statutory Tax And Effective Tax Rate [Table Text Block] Concentration risk, credit risk, financial instruments, off-balance sheet risk Letters Of Credit, Off-Balance Sheet Risk Letters of credit with off-balance sheet credit risk (standby letters of credit). These letters of credit mitigate the risk if the Company were to fail to reimburse the third party for worker's compensation claims. Schedule of Lessee, Operating Lease, Liability, Maturity Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Document Period End Date Document Period End Date Revenues, other than interest on funds held for clients and PEO revenues Revenues, Other Than Interest on Funds Held For Clients and PEO Revenues [Member] Revenues, Other Than Interest on Funds Held For Clients and PEO Revenues 364-Day Credit Agreement Three Hundred And Sixty Four Day Credit Facility [Member] Three hundred and sixty four day credit facility [Member] Debt instrument, face amount Debt Instrument, Face Amount Twelve months ending June 30, 2028 Lessee, Operating Lease, Liability, to be Paid, Year Two Debt instrument, term Debt Instrument, Term Effective Interest Rate Debt Instrument, Interest Rate, Effective Percentage Assets held-for-sale, long lived, fair value Long-Lived Asset, Held-for-Sale, Fair Value Disclosure Tax effect OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax Deferred tax assets, operating loss carryforwards Net operating losses Deferred Tax Assets, Operating Loss Carryforwards Payments for reinsurance Payments for Reinsurance U.S. Federal Income Tax Paid, Federal, after Refund Received Accumulated other comprehensive (loss)/income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Other Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Current operating lease liability Operating Lease, Liability, Current Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] (Increase)/decrease in accounts receivable Increase (Decrease) in Accounts and Notes Receivable Total liabilities Liabilities Trading Symbol Trading Symbol Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Unrecognized Tax Benefits [Roll Forward] Capitalized Contract Cost [Axis] Capitalized Contract Cost [Axis] Revenue, incremental costs of obtaining a contract, period of recognition Revenue, Incremental Costs of Obtaining a Contract, Period of Recognition Revenue, Incremental Costs of Obtaining a Contract, Period of Recognition Income taxes payable Accrued Income Taxes, Current Schedule of Preliminary Purchase Price Allocation Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Company Selected Measure Name Company Selected Measure Name Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Reclassification adjustments to net earnings Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Tax Contingency, Percent Cash Flows from Operating Activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Fair value of plan assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Property, plant and equipment, useful life Property, Plant, and Equipment, Useful Life Other Deferred Tax Assets, Other Reclassification out of Accumulated Other Comprehensive Income [Abstract] Reclassification out of Accumulated Other Comprehensive Income [Abstract] Reclassification out of Accumulated Other Comprehensive Income [Abstract] U.S. Treasury securities US Treasury Securities [Member] Operating loss carryforwards Operating Loss Carryforwards Debt instrument, maturity period Debt Instrument, Maturity Period Debt Instrument, Maturity Period Dividends payable Dividends Payable Expected tax deductible amount Business Combination, Goodwill, Expected Tax Deductible, Amount Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Interest on funds held for clients Interest On Funds Held For Clients [Member] Interest On Funds Held For Clients Other intangibles Other Intangible Assets [Member] Total corporate investments and funds held for clients - gross unrealized losses Total Corporate Investments And Funds Held For Clients Gross Unrealized Losses Total corporate investments and funds held for clients - gross unrealized losses Purchase price of common stock as percentage of market value Percentage Of Market Value Paid For Company Stock Percentage Of Market Value Paid For Company Stock Derivative Instrument, Termination [Axis] Derivative Instrument, Termination [Axis] Derivative Instrument, Termination Cash paid for operating lease liabilities Operating Lease, Payments Award Timing Predetermined Award Timing Predetermined [Flag] Aggregate intrinsic value for options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Stock-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Fair Value, Inputs, Level 1 Level 1 Fair Value, Inputs, Level 1 [Member] Software, Internally Developed Software, Internally Developed [Member] Tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Amount Effective tax rate Effective tax rate Effective Income Tax Rate Reconciliation, Percent Deferred tax liabilities: Deferred Tax Liabilities, Gross [Abstract] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Long-term debt, fair value Long-Term Debt, Fair Value Plan Name [Domain] Plan Name [Domain] Weighted Average Price, beginning of period (in dollars per share) Weighted Average Price, end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Total net assets acquired Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Summary of Deferred Costs Capitalized Contract Cost [Table Text Block] Corporate Investments and Funds Held For Clients Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Expiration Date Trading Arrangement Expiration Date Foreign Current Foreign Tax Expense (Benefit) Percent of level two investment pricing inputs provided by independent pricing service (over) Percent of Level Two Investment Pricing Inputs Provided by Pricing Service Percent of Level Two Investment Pricing Inputs Provided by Pricing Service Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] State Current State and Local Tax Expense (Benefit) Restricted cash and restricted cash equivalents included in funds held for clients Restricted cash and cash equivalents held to satisfy client funds obligations Restricted Cash and Cash Equivalent Additions and other adjustments Goodwill, Other Increase (Decrease) Money market securities and other cash equivalents - fair value Cash and Cash Equivalents, Fair Value Disclosure Buildings Building [Member] Number of Options, options exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Schedule of Performance Based Restricted Shares and Units Performance Based Restricted Shares And Units [Table Text Block] Disclosure of the number for Performance-Based restricted stock and Performance based restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock and restricted stock units that were granted, vested, or forfeited during the year. Accounts receivable, net of allowance for doubtful accounts Business Combination, Recognized Asset Acquired, Receivable, Current Purchase commitments relating to 2030 and 2031 Unrecorded Unconditional Purchase Obligation, To Be Paid, Year Four Through Five Unrecorded Unconditional Purchase Obligation, To Be Paid, Year Four Through Five Cash Flows from Investing Activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Entity Voluntary Filers Entity Voluntary Filers Remaining lease term Lessee, Operating Lease, Remaining Lease Term Total remaining unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount After four years Available For Sale Securities Debt Maturities Due After Four Fair Value This item represents the fair value of debt securities which are expected to mature after four years of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities. Proceeds from the sales and maturities of corporate and client funds marketable securities Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale Document Financial Statement Error Correction [Flag] Document Financial Statement Error Correction [Flag] Segments [Domain] Segments [Domain] Property, Plant and Equipment Property, Plant, and Equipment [Policy Text Block] Debt Debt Disclosure [Text Block] Highly compensated employee contribution percentage to retirement and saving plan Highly Compensated Employee Contribution Percentage To Retirement And Saving Plan Highly Compensated Employee Contribution Percentage To Retirement And Saving Plan Change in plan assets: Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Business Combination [Table] Business Combination [Table] Deferred income taxes Deferred Income Tax Expense (Benefit), Net Of Disposals Deferred Income Tax Expense (Benefit), Net Of Disposals PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] TOTAL EXPENSES Costs and Expenses Interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Dividends Dividends, Common Stock, Cash Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent Currency translation adjustments Contract With Customer, Liability, Increase (Decrease) From Foreign Currency Translation Contract With Customer, Liability, Increase (Decrease) From Foreign Currency Translation Noncurrent assets Assets for Plan Benefits, Defined Benefit Plan Assets Assets [Abstract] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost Insider Trading Policies and Procedures [Line Items] Allowance for doubtful accounts, current Accounts Receivable, Allowance for Credit Loss, Current Total deferred Deferred Income Tax Expense (Benefit) Options excluded from the calculation of diluted earnings per share because their exercise prices exceeded the average market price (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Changes in Goodwill Goodwill [Table Text Block] Auditor Location Auditor Location Entity Central Index Key Entity Central Index Key Less: accumulated depreciation Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Capital in excess of par value Additional Paid in Capital, Common Stock Canadian provincial bonds Canadian Provincial Bonds [Member] Canadian Provincial Bonds [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] Client funds obligations Client funds obligations Represent the Company's contractual obligations to remit funds to satisfy clients' payroll and tax payment obligations and are recorded on the Balance Sheet at the time that the Company impounds funds from clients. U.S. Federal Statutory Tax Rate Provision for taxes at U.S. statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount PEO revenues PEO Revenues [Member] PEO Revenues Fixed-rate 4.75% notes due May 8, 2032 Notes Due In 2032 [Member] Notes Due In 2032 Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Expected long-term rate of return on assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets Schedule of Components of Provision (Benefit) for Income Taxes Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table Text Block] Number of Options (in thousands) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Income Tax Examination [Line Items] Income Tax Examination [Line Items] Accumulated Other Comprehensive Income/(Loss) Accumulated Other Comprehensive Income/(Loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Dividends paid Payments of Dividends Balance at beginning of year Balance at end of year SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Restricted short-term and long term marketable securities held to satisfy client funds obligations Debt Securities, Available-for-Sale, Restricted Weighted-average remaining requisite vesting period Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Contingencies Commitments and Contingencies, Policy [Policy Text Block] Long-term marketable securities Marketable Securities, Noncurrent Statement [Line Items] Statement [Line Items] Undistributed earnings of foreign subsidiaries Undistributed Earnings of Foreign Subsidiaries Total assets Assets Assets Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan [Table] Derivative Instrument, Termination Two Derivative Instrument, Termination Two [Member] Derivative Instrument, Termination Two Summary of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Plan assets Fair value of plan assets at beginning of year Fair value of plan assets at end of year Defined Benefit Plan, Plan Assets, Amount Operating Segments Operating Segments [Member] Weighted average fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Reclassification of realized net (gains)/losses on available-for-sale securities to net earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Gross Unrealized  Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Total liabilities assumed Business Combination, Recognized Liability Assumed, Liability Foreign tax effects Foreign rate differential Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent PEO PEO [Member] Short-term marketable securities Short-term marketable securities (a) Marketable Securities, Current Other liabilities Other Liabilities, Noncurrent Goodwill Beginning balance Ending balance Goodwill Fixed income securities U.S. fixed income securities and cash Fixed Income Securities [Member] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Tax Contingency, Amount Retained Earnings Retained Earnings [Member] Operating lease liabilities Operating Lease, Liability, Noncurrent Tax on unrepatriated earnings Deferred Tax Liabilities, Undistributed Foreign Earnings Money market securities, cash and other cash equivalents Money Market Funds [Member] Software and software licenses Software, In-Development, Internally Developed, and Purchased [Member] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, shares outstanding Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Currency Translation Adjustment Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Unrecognized tax benefits, interest benefit on income taxes expense Unrecognized Tax Benefits, Interest Benefit On Income Taxes Expense Unrecognized Tax Benefits, Interest Benefit On Income Taxes Expense Corporate bonds Corporate Debt Securities [Member] DILUTED EARNINGS PER SHARE (in dollars per share) Earnings Per Share, Diluted Short-term marketable securities under reverse repurchase agreements Short-Term Marketable Securities Under Reverse Repurchase Agreements Short-Term Marketable Securities Under Reverse Repurchase Agreements Contract liability, net of revenue recognized on contracts during the year Contract With Customer, Liability, Deferral Net Of Revenue Recognized And Foreign Currency Translation Amount of revenue deferred as an obligation to transfer good or service to customer for which consideration from customer has been received or is due, net of the amount of revenue recognized in the period from deferrals during the period. Amortization of intangible assets Intangible Asset, Finite-Lived, Amortization Expense Intangible Asset, Finite-Lived [Line Items] Intangible Asset, Finite-Lived [Line Items] Tax effect Reclassification from AOCI, Current Period, Tax Fixed-rate 4.45% notes due September 9, 2034 Notes Due In 2034 [Member] Notes Due In 2034 Revenues Revenue from Contract with Customer, Excluding Assessed Tax Term of credit Line Of Credit Facility Term Of Credit Line Of Credit Facility Term Of Credit Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Recently Issued Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Table Text Block] Mortgage-backed security bonds Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member] International equity securities Defined Benefit Plan, Equity Securities, Non-US [Member] Total corporate investments and funds held for clients - gross unrealized gains Total Corporate Investments And Funds Held For Clients Gross Unrealized Gains Total corporate investments and funds held for clients - gross unrealized gains Depreciation and amortization Cost, Depreciation and Amortization State and local income taxes, net of federal income tax effect State taxes, net of federal tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount All other liabilities Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Liabilities, Other Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Liabilities, Other Capitalized Contract Cost [Table] Capitalized Contract Cost [Table] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Foreign Tax Authority Income Tax Jurisdiction, Foreign [Member] Auditor Firm ID Auditor Firm ID Expected future plan benefit payment - 2032 to 2036 Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Foreign Income Tax Paid, Foreign, after Refund Received Time-Based Restricted Stock Time-based restricted shares/units Time Based Restricted Stock [Member] Time-Based Restricted Stock [Member] Acquisitions Business Combination [Text Block] Expected future plan benefit payment - 2031 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Description of Business Description of Business [Policy Text Block] Description of Business Total corporate investments and funds held for clients - amortized cost Total Corporate Investments And Funds Held For Clients Amortized Cost Total corporate investments and funds held for clients - amortized cost Canadian government obligations and Canadian government agency obligations Debt Security, Government, Non-US [Member] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service cost Service cost – benefits earned during the year Defined Benefit Plan, Service Cost Income Tax Examination [Table] Income Tax, Examination [Table] Funds Held for Clients Funds Held For Clients [Member] Funds held for clients [Member] Common stock, shares issued Common stock, shares issued, beginning of period Common stock, shares issued, end of period Common Stock, Shares, Issued Asset-Backed Securities, Device Payment Plan Agreement Receivables Asset-Backed Securities, Device Payment Plan Agreement Receivables [Member] Asset-Backed Securities, Device Payment Plan Agreement Receivables Securities in unrealized loss position greater than 12 months, gross unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Derivative Instrument, Termination One Derivative Instrument, Termination One [Member] Derivative Instrument, Termination One Product and Service [Domain] Product and Service [Domain] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Deferred tax valuation allowance SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] Deferred income taxes Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Defined contribution plan, cost Defined Contribution Plan, Cost Performance-based restricted shares/units Performance Based Restricted Stock [Member] Performance-based restricted stock [Member] Twelve months ending June 30, 2029 Lessee, Operating Lease, Liability, to be Paid, Year Three Termination Date Trading Arrangement Termination Date Identifiable intangible assets Estimated Fair Value Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived U.S. Federal Statutory Tax Rate Provision for taxes at U.S. statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Funds held for clients held-in grantor trust Client Funds Held In Grantor Trust Client Funds Held In Grantor Trust Accrued expenses and other current liabilities Accrued Liabilities, Current Entity Public Float Entity Public Float Fair Value as of Grant Date Award Grant Date Fair Value Federal Farm Credit Banks Federal Farm Credit Banks [Member] Federal Farm Credit Banks [Member] Schedule of Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Gain on sale of assets Gain (Loss) on Disposition of Assets Schedule of Goodwill [Table] Goodwill [Table] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Deferred revenue Business Combination, Recognized Liability Assumed, Deferred Revenue, Current Operating expenses Operating Costs and Expenses Arrangement Duration Trading Arrangement Duration Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Securities in unrealized loss position less than 12 months, gross unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Aggregate intrinsic value of stock options outstanding and exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Revenues Revenues Total - gross Intangible Asset, Finite-Lived, before Accumulated Amortization Workers' compensation coverage and state unemployment taxes Worker's Compensation Coverage And State Unemployment Taxes Worker's Compensation Coverage And State Unemployment Taxes Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Deferred income taxes, net of valuation allowance Business Combination, Recognized Asset Acquired, Deferred Tax Asset Vesting term options granted Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Goodwill [Roll Forward] Goodwill [Roll Forward] Furniture and fixtures Furniture, leaseholds and other Furniture and Fixtures [Member] Intangible Asset, Finite-Lived, Class [Domain] Intangible Asset, Finite-Lived, Class [Domain] Options, exercisable, weighted average remaining contractual term Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted-Average Remaining Contractual Term Total corporate investments and funds held for clients - fair value Total Corporate Investments And Funds Held For Clients Fair Value Total corporate investments and funds held for clients - fair value Tradename Trade Names [Member] Share-based Compensation Arrangements by Share-based Payment Award, Award Type and Plan Name [Domain] Award Type [Domain] Award Type [Domain] Total current assets before funds held for clients Total Assets Before Funds Held Clients Total assets before funds held for clients Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Fair Value, Inputs, Level 3 Level 3 Fair Value, Inputs, Level 3 [Member] U.S. government agency securities U.S. government agency securities US Government Agencies Debt Securities [Member] Expiration of the statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Twelve months ending June 30, 2027 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year One Treasury stock, shares repurchased (in shares) Treasury Stock, Shares, Acquired Geographical [Axis] Geographical [Axis] Increase in accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities Non-service components of pension income, net Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Contract liability, July 1, 2025 Contract liability, June 30, 2026 Contract with Customer, Liability Unrealized investment losses, net Deferred Tax Asset, Debt Securities, Trading, Unrealized Loss Schedule of Short-term Debt [Table] Short-Term Debt [Table] Deductions SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction Treasury stock acquired Treasury Stock, Value, Acquired, Cost Method Cash, cash equivalents, restricted cash, and restricted cash equivalents, beginning of year Cash, cash equivalents, restricted cash, and restricted cash equivalents, end of year Total cash, cash equivalents, restricted cash, and restricted cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Customer contracts and lists Customer Lists [Member] Schedule of Finite-Lived Intangible Assets by Major Class [Table] Intangible Asset, Finite-Lived [Table] Schedule of Changes in Accumulated Other Comprehensive Income (“AOCI”) Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Non-NEOs Non-NEOs [Member] Purchase price Payments to Acquire Businesses, Gross Expected future plan benefit payment - 2027 Defined Benefit Plan, Expected Future Benefit Payment, Year One Twelve months ending June 30, 2028 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Two Revenue, service agreements, term Revenue, Service Agreements, Term Revenue, Service Agreements, Term Schedule of Debt Schedule of Debt [Table Text Block] Leases Lessee, Operating Leases [Text Block] Long-Term Debt, Type [Domain] Long-Term Debt, Type [Domain] Schedule of Stock-Based Compensation Expense Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block] Repurchases of common stock Payments for Repurchase of Common Stock Short-term deferred revenues Contract with Customer, Liability, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Accumulated benefit obligation Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] Award Type [Axis] Award Type [Axis] Unrealized net gains/(losses) on cash flow hedging activities Unamortized gain on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Product and Service [Axis] Product and Service [Axis] PEO zero-margin benefits pass-throughs PEO Zero-Margin Benefits Pass-Throughs [Member] PEO Zero-Margin Benefits Pass-Throughs Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Short-term Debt [Line Items] Short-Term Debt [Line Items] Common Stock Common Stock [Member] Fair Value Debt securities, available-for-sale Total available-for-sale securities Debt Securities, Available-for-Sale Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Nontaxable or nondeductible items Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent Operating lease cost Operating Lease, Cost Current: Current Federal, State and Local, Tax Expense (Benefit) [Abstract] Supranational Bonds Supranational Bonds [Member] Supranational Bonds Purchase commitments relating to 2027 Unrecorded Unconditional Purchase Obligation, to be Paid, Year One Land and buildings Land and Building [Member] Currency translation adjustments Goodwill, Foreign Currency Translation, Gain (Loss) Time-Based Restricted Stock Units Time-Based Restricted Stock Units [Member] Time-Based Restricted Stock Units [Member] Realized (gains)/losses on available-for-sale securities, net Debt Securities, Available-for-Sale, Realized Gain (Loss) Total liabilities and stockholders’ equity Liabilities and Equity Variable lease cost Variable Lease, Cost Curtailments and special termination benefits Defined Benefit Plan, Benefit Obligation, Curtailment And Special Termination Benefits Defined Benefit Plan, Benefit Obligation, Curtailment And Special Termination Benefits Employee Stock Option Share-Based Payment Arrangement, Option [Member] Deferred tax assets, operating loss carryforwards, subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration Schedule of Assumptions Used Defined Benefit Plan, Assumptions [Table Text Block] Segments [Axis] Segment Reporting Information, by Segment [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Tabular List, Table Tabular List [Table Text Block] SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] Additions to intangibles Payments to Acquire Intangible Assets Corporate Investments And Funds Held For Clients [Abstract] Corporate Investments And Funds Held For Clients [Abstract] Corporate Investments and Funds Held for Clients [Abstract] Twelve months ending June 30, 2029 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Three Name Awards Close in Time to MNPI Disclosures, Individual Name 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] Deferred tax assets: Deferred Tax Assets, Gross [Abstract] Property, Plant and Equipment Property, Plant and Equipment [Member] Property, Plant and Equipment, Type [Domain] Long-Lived Asset, Class [Domain] Schedule of Property, Plant and Equipment [Table] Property, Plant, and Equipment [Table] Preferred stock, $1.00 par value: Authorized, 0.3 shares; issued, none Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Schedule of Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] 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 Special termination benefits, plan curtailments, and settlement charges Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment Schedule II - Valuation and Qualifying Accounts SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Name Measure Name Pay vs Performance Disclosure [Line Items] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Fixed Rate Credit Card Fixed Rate Credit Card [Member] Fixed Rate Credit Card [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] United States Income (Loss) from Continuing Operations before Income Taxes, Domestic Capital in Excess of Par Value Additional Paid-in Capital [Member] Name Trading Arrangement, Individual Name Projected benefit obligation Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation Cash and cash equivalents Money market securities, cash and other cash equivalents - amortized cost Cash and Cash Equivalent Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Axis] Operating Segments, Excluding Intersegment Elimination Operating Segments, Excluding Intersegment Elimination [Member] Operating Segments, Excluding Intersegment Elimination Company Selected Measure Amount Company Selected Measure Amount Short-Term Financing Short-Term Debt [Text Block] Depreciation and amortization Total depreciation and amortization Depreciation, Depletion and Amortization Retirement Plan Sponsor Location [Domain] Retirement Plan Sponsor Location [Domain] Weighted average remaining life of stock options outstanding and exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Target asset allocation Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Two years to three years Available For Sale Securities Debt Maturities Due After Two Year Up To Three Fair Value This item represents the fair value of debt securities which are expected to mature after two years up to three years of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities. Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Weighted-average remaining lease term (in years) Operating Lease, Weighted Average Remaining Lease Term Non-PEO NEO Non-PEO NEO [Member] Accounting Policies [Table] Accounting Policies [Table] Accounting Policies Depreciation expense Depreciation, Nonproduction Three years to four years Available For Sale Securities Debt Maturities Due After Three Year Up To Four Fair Value This item represents the fair value of debt securities which are expected to mature after three years up to four years of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities. Other (Income)/Expense, Net Other Income and Other Expense Disclosure [Text Block] TOTAL COSTS OF REVENUES Cost of Product and Service Sold SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Technology Technology-Based Intangible Assets [Member] Award Timing Method Award Timing Method [Text Block] Net change in cash, cash equivalents, restricted cash, and restricted cash equivalents 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] Deferred tax assets, gross Deferred Tax Assets, Gross Long-term deferred tax assets Deferred tax assets, net Deferred Tax Assets, Net of Valuation Allowance Net amortization and deferral Defined Benefit Plan, Amortization of Gain (Loss) NET EARNINGS Net earnings Basic and diluted, net earnings Net Income (Loss) Attributable to Parent Long-Term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Balance Sheet Location [Axis] Location, Statement of Financial Position, Balance [Axis] Proceeds from the sale of property, plant, and equipment and other assets Proceeds from Sale of Property, Plant, and Equipment Expected future plan benefit payment - 2030 Defined Benefit Plan, Expected Future Benefit Payment, Year Four Restatement Determination Date: Restatement Determination Date [Axis] Weighted Average Price, option exercisable (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Litigation settlement amount awarded to other party Litigation Settlement, Amount Awarded to Other Party Actuarial loss/(gain) Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Leases Lessee, Leases [Policy Text Block] Purchase commitments relating to 2028 and 2029 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two Through Three Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two Through Three Deferred costs to obtain a contract Deferred costs to obtain a contract [Member] Deferred costs to obtain a contract [Member] REVENUES: Revenues [Abstract] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Maturities of short-term funding agreements (up to) Maturities Of Short Term Funding Agreements Maturities Of Short-Term Funding Agreements Statistical Measurement [Domain] Statistical Measurement [Domain] Document Fiscal Year Focus Document Fiscal Year Focus Revenue, remaining performance obligation, expected timing of satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Schedule of Commercial Paper Program Commercial Paper Program [Table Text Block] Commercial Paper Program Number of Shares/Units (in thousands) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Table Text Block] Common stock, $0.10 par value: authorized,1,000.0 shares; issued, 638.7 shares at June 30, 2026 and June 30, 2025; outstanding, 397.8 and 405.3 shares at June 30, 2026 and June 30, 2025, respectively Common Stock, Value, Issued Twelve months ending June 30, 2027 Lessee, Operating Lease, Liability, to be Paid, Year One Interest expense Interest Expense, Operating and Nonoperating Settlement with tax authorities Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Net (payments)/proceeds from issuance of commercial paper Proceeds from (Repayments of) Commercial Paper Restatement Determination Date Restatement Determination Date Commingled trusts Comingled Trusts [Member] Comingled Trusts Tax Jurisdiction of Domicile [Extensible Enumeration] Tax Jurisdiction of Domicile [Extensible Enumeration] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Data processing equipment Data Processing Equipment [Member] Data Processing Equipment [Member] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Net (gain)/loss on ADP Ventures' investments Gain (Loss) On Alternative Investment Gain (Loss) On Alternative Investment Unrecognized tax benefits, interest on income taxes accrued Unrecognized Tax Benefits, Interest on Income Taxes Accrued Amendment Flag Amendment Flag Goodwill [Line Items] Goodwill [Line Items] Current liabilities: Liabilities, Current [Abstract] Bad debt expense Accounts Receivable, Credit Loss Expense (Reversal) Marketable Securities [Line Items] Marketable Securities [Line Items] Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Goodwill Goodwill and Intangible Assets, Policy [Policy Text Block] Schedule of Debt Securities, Available-for-sale Debt Securities, Available-for-Sale [Table Text Block] Investment Type Categorization [Domain] Investments [Domain] Capital expenditures Payments to Acquire Other Property, Plant, and Equipment Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Expected future plan benefit payment - 2029 Defined Benefit Plan, Expected Future Benefit Payment, Year Three Property, Plant, and Equipment [Abstract] Property, Plant, and Equipment [Abstract] Entity Address, State or Province Entity Address, State or Province PEO Total Compensation Amount PEO Total Compensation Amount Additions for tax positions of prior periods Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Basic weighted average shares outstanding (in shares) Basic, weighted shares (in shares) Weighted Average Number of Shares Outstanding, Basic SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] Twelve months ending June 30, 2030 Lessee, Operating Lease, Liability, to be Paid, Year Four SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] Performance Based Restricted Stock and Units Performance Based Restricted Stock Units [Member] Performance Based Restricted Stock Units [Domain] Schedule of Income Taxes Paid (Refunded) Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Tax effect Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Obligations under commercial paper borrowings Commercial paper outstanding Commercial Paper Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Restricted units vested Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Fixed-rate 1.70% notes due May 15, 2028 Notes due on 2028 [Member] Notes due on 2028 Corporate Investments Corporate Investments [Member] Corporate investments [Member] Net pension (income)/expense Increase (Decrease) in Obligation, Pension Benefits Total - accumulated amortization Intangible Asset, Finite-Lived, Accumulated Amortization Maximum borrowing capacity under credit facilities Line of Credit Facility, Maximum Borrowing Capacity Schedule of Defined Benefit Plan Assumptions Used Calculating Net Pension (Income)/Expense Defined Benefit Plan Assumptions Used Calculating Net Pension Expense [Table Text Block] Defined Benefit Plan Assumptions Used Calculating Net Pension Expense [Text Block] Credit Facility Expiring In June 2031 Credit Facility Expiring In June 2031 [Member] Credit Facility Expiring In June 2031 Settlement of cash flow hedges (Payments For) Proceeds From Settlement Of Cash Flow Hedges (Payments For) Proceeds From Settlement Of Cash Flow Hedges Treasury stock - at cost: 240.9 and 233.4 shares at June 30, 2026 and June 30, 2025, respectively Treasury Stock, Value Recently Issued Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Earnings Per Share ("EPS") Earnings Per Share, Policy [Policy Text Block] Schedule of Estimated Useful Lives Estimated Useful lives [Table Text Block] [Table Text Block] for Estimated Useful lives for Property, Plant, and Equipment [Table] Tax effect Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Domestic Plan Domestic Plan [Member] Less segment expenses: Segment Reporting, Reconciliation [Abstract] Prior service cost included in accumulated other comprehensive income (loss) Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax Property, Plant and Equipment Property, Plant, and Equipment [Text Block] Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net cash flows used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Unrecognized tax benefits Unrecognized tax benefits at beginning of the year Unrecognized tax benefit at end of year Unrecognized Tax Benefits Increase in deferred contract costs Increase (Decrease) in Contract with Customer, Asset EXPENSES: Costs and Expenses [Abstract] Security Exchange Name Security Exchange Name Currency translation adjustments Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss) Schedule of Income Tax From Continuing Operations Provision for Income Tax Components Disclosure Income Tax From Continuing Operations Provision For Income Tax Components Disclosure [Table Text Block] Earnings from Continuing Operations by Geographic Location Purchases of corporate and client funds marketable securities Payments to Acquire Marketable Securities Authorized for issuance under the employee stock purchase plan (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Securities in unrealized loss position greater than 12 months, fair market value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Schedule of Property, Plant and Equipment Property, Plant, and Equipment [Table Text Block] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Marketable Securities [Table] Marketable Securities [Table] Name Outstanding Recovery, Individual Name Tax effect Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] State Deferred State and Local Income Tax Expense (Benefit) Employer Services Employer Services Employer Services Segment [Member] Employer Services Segment. Geographical [Domain] Geographical [Domain] 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] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] WorkForce Software WorkForce Software [Member] WorkForce Software Federal Home Loan Banks Federal Home Loan Bank Certificates and Obligations (FHLB) [Member] Current liabilities Liability, Defined Benefit Pension Plan, Current Pension Liability Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Asset Class [Domain] Asset Class [Domain] Compensation Amount Outstanding Recovery Compensation Amount Amortization of deferred contract costs Capitalized Contract Cost, Amortization Individual: Individual [Axis] Other Other Geographical Places [Member] Other Geographical Places [Member] Diluted weighted average shares outstanding (in shares) Diluted, weighted average shares (in shares) Weighted Average Number of Shares Outstanding, Diluted Schedule of Net Funded Status Schedule of Net Funded Status [Table Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Foreign Currency Risk Management Programs and Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Commercial Paper Commercial Paper [Member] Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Employer contributions Employer contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Credit Facility Expiring In June 2030 Credit Facility Expiring In June 2030 [Member] Revenue from Contract with Customer [Abstract] Income tax benefit Share-Based Payment Arrangement, Exercise of Option, Tax Benefit Discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Costs of revenues: Cost of Revenue [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) Treasury Stock Treasury Stock, Common [Member] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Letters of credit outstanding, amount Letters of Credit Outstanding, Amount Total undiscounted lease obligations Lessee, Operating Lease, Liability, to be Paid Effect of employee stock option shares, weighted average shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants PEO PEO Services Professional Employee Organization Services Segment [Member] Professional Employee Organization Services Segment [Member] All Executive Categories All Executive Categories [Member] Net actuarial loss included in accumulated other comprehensive income (loss) Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Schedule of Net Pension (Income)/ Expense Schedule of Net Benefit Costs [Table Text Block] Selling and marketing Selling and Marketing Expense Reconciliation of cash, cash equivalents, restricted cash, and restricted cash equivalents to the Consolidated Balance Sheets Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Financial Data by Segment and Geographic Area Segment Reporting [Text Block] Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Auditor Name Auditor Name Summary of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Effect of exchange rate changes on cash, cash equivalents, restricted cash, and restricted cash equivalents Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line [Axis] Location, Statement of Income, Balance [Axis] Diluted, EPS (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Basic, EPS (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] 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] Maximum percentage that will ultimately vest under performance-based restricted stock awards based on performance target Maximum percentage that will ultimately vest under performance-based restricted stock awards based on performance target Maximum percentage that will ultimately vest under performance-based restricted stock awards based on performance target Business Combination [Line Items] Business Combination [Line Items] Net pension (income)/expense Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Common stock, shares authorized Common Stock, Shares Authorized Weighted average remaining useful life Estimated Useful Life (in years) Intangible Asset, Finite-Lived, Useful Life Revenue, capitalized costs fulfillment period Revenue, Costs to Fulfill a Contract, Period Revenue, Costs to Fulfill a Contract, Period Net (payments)/proceeds related to reverse repurchase agreements Net (Payments Of)/Proceeds From Reverse Repurchase Agreements Net (Payments Of)/Proceeds From Reverse Repurchase Agreements Exercise Price Award Exercise Price Fixed-rate 5.00% notes due May 7, 2036 Notes Due In 2036 [Member] Notes Due In 2036 Zero-margin benefits pass-through costs Zero-Margin Benefits Pass-Through Costs Zero-Margin Benefits Pass-Through Costs Segment Reporting [Line Items] Segment Reporting [Line Items] 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] Prepaid retirement benefits Deferred Tax Liabilities, Tax Deferred Expense, Compensation And Benefits, Postretirement Benefits Deferred Tax Liabilities, Tax Deferred Expense, Compensation And Benefits, Postretirement Benefits Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Employee Benefit Plans Compensation and Employee Benefit Plans [Text Block] Payments of debt Repayments of Long-Term Debt Less: unamortized discount and debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Equity Component [Domain] Equity Component [Domain] Adoption Date Trading Arrangement Adoption Date Summary of Other (income)/expense, net Schedule of Other Nonoperating Income (Expense) [Table Text Block] Other (income)/expense, net Other (income)/expense, net Nonoperating Income (Expense) Revenues from external customers Revenues, Other Than Interest On Funds Held For Client [Member] Revenues, Other Than Interest On Funds Held For Client Foreign tax credits Deferred Tax Assets, Tax Credit Carryforwards, Foreign Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Net lease obligations Operating Lease, Liability U.S. equity securities Defined Benefit Plan, Equity Securities, US [Member] Beginning balance, options outstanding (in shares) Ending balance, options outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Reverse Repurchase Agreements Reverse Repurchase Agreements [Member] Reverse Repurchase Agreements [Member] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Threshold of coverage for all losses per occurrence covered by reinsurance arrangement, next fiscal year Threshold of coverage for all losses per occurrence covered by reinsurance arrangement, next fiscal year Threshold of coverage for all losses per occurrence covered by reinsurance arrangement, next fiscal year Fixed and intangible assets Deferred Tax Assets, Fixed And Intangible Assets Deferred Tax Assets, Fixed And Intangible Assets Selling, general, and administrative expenses Selling, General and Administrative Expense Expected future plan benefit payment - 2028 Defined Benefit Plan, Expected Future Benefit Payment, Year Two Business Combination [Domain] Business Combination [Domain] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Minimum percentage that will ultimately vest under performance-based restricted stock awards based on performance target Minimum percentage that will ultimately vest under performance-based restricted stock awards based on performance target Minimum percentage that will ultimately vest under performance-based restricted stock awards based on performance target. Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] All Adjustments to Compensation All Adjustments to Compensation [Member] Business Combination [Axis] Business Combination [Axis] Effect of cross-border tax laws Effective Income Tax Rate Reconciliation, Cross-Border Tax Effect, Amount Income Taxes Income Tax, Policy [Policy Text Block] Net cash flows provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Stockholders' equity: Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Debt Security, Corporate, Non-US Debt Security, Corporate, Non-US [Member] Intercompany eliminations Intersegment Eliminations [Member] Schedule of Reverse Repurchase Agreement Reverse Repurchase Agreement [Table Text Block] Reverse Repurchase Agreement Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] City Area Code City Area Code Noncurrent liabilities Liability, Defined Benefit Pension Plan, Noncurrent Name Forgone Recovery, Individual Name Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Cash and cash equivalents under reverse repurchase agreements Cash And Cash Equivalents Under Reverse Repurchase Agreements Cash And Cash Equivalents Under Reverse Repurchase Agreements Preferred stock, shares issued Preferred Stock, Shares Issued Cash payments related to the settlement of restricted stock units Employee Benefits and Share-Based Compensation Stock-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Pension plans asset allocations Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Increase in other assets Increase (Decrease) in Other Operating Assets Net deferred tax (liabilities)/assets Deferred Tax Liabilities, Net Benefit obligation at beginning of year Projected benefit obligation at end of year Defined Benefit Plan, Benefit Obligation Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Total pretax stock-based compensation expense Share-Based Payment Arrangement, Expense Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Number of fixed rate notes issued Number Of Fixed Rate Notes Issued Number Of Fixed Rate Notes Issued Options exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Deferred costs to fulfill a contract Deferred costs to fulfill a contract [Member] Deferred costs to fulfill a contract [Member] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Total corporate investments Investments Unrealized net gains/(losses) on available-for-sale securities OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax One year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Recognition of revenue included in beginning of year contract liability Contract with Customer, Liability, Revenue Recognized Subsequent Event Type [Domain] Subsequent Event Type [Domain] Charged to costs and expenses SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense Net Gains/(Losses) on Available-for-sale Securities AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Cash Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Derivative Instrument, Termination [Domain] Derivative Instrument, Termination [Domain] Derivative Instrument, Termination Entity Current Reporting Status Entity Current Reporting Status Interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate Net cash flows provided by/(used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Reclassification out of Accumulated Other Comprehensive Income ("AOCI") Disclosure of Reclassification Amount [Text Block] Total Shareholder Return Amount Total Shareholder Return Amount Total pension asset investments Total Pension Assets Excluding Cash [Member] Total Pension Assets Excluding Cash [Member] Fair value of plan assets Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets Schedule of Purchase Price, Net of Cash Acquired Business Combination [Table Text Block] Research and development Research and Development Expense Adjustments to reconcile net earnings to cash flows provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Cash Flows from Financing Activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property, plant and equipment, net Property, plant and equipment, net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Interest cost Interest cost on projected benefits Defined Benefit Plan, Interest Cost U.S. State Income Tax Paid, State and Local, after Refund Received Financial Instruments [Domain] Financial Instruments [Domain] Intangible Asset, Finite-Lived, Class [Axis] Intangible Asset, Finite-Lived, Class [Axis] Goodwill and Intangible Assets, Net Intangible Asset and Goodwill [Text Block] Underlying Securities Award Underlying Securities Amount Revenue Revenue from Contract with Customer [Text Block] Income Tax Jurisdiction, Domestic State and Local Income Tax Jurisdiction, Domestic State and Local [Member] Other Payment for (Proceeds from) Other Investing Activity Weighted-average discount rate Operating Lease, Weighted Average Discount Rate, Percent Segment Reporting [Table] Segment Reporting [Table] Shares available for future grants (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Long-term marketable securities under reverse repurchase agreements Long-Term Marketable Securities Under Reverse Repurchase Agreements Long-Term Marketable Securities Under Reverse Repurchase Agreements Schedule of Lease, Cost Lease, Cost [Table Text Block] Other current assets Other Assets, Current Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Securities in unrealized loss position less than 12 months, fair market value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Tax effect Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Current Fiscal Year End Date Current Fiscal Year End Date Unrecognized tax benefits, interest on income taxes expense Unrecognized Tax Benefits, Interest on Income Taxes Expense Operating loss carry forwards not subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount HCM HCM [Member] HCM [Member] Asset Backed Auto Loan Receivables Asset Backed Auto Loan Receivables [Member] Asset Backed Auto Loan Receivables Schedule of Expected Maturities of Available-for-Sale Securities Schedule Of Expected Maturities Of Available For Sale Securities [Table Text Block] This element represents the expected maturities broken out by maturity date of all investments categorized as available-for-sale Purchase commitments Unrecorded Unconditional Purchase Obligation Summary of Significant Accounting Policies [Line Items] Property, Plant and Equipment and intangibles [Line Items] Property, Plant and Equipment and intangibles [Line Items] 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] Dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Issuances relating to stock compensation plans Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Long-term Non-current [Member] Non-current [Member] All other assets Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Assets, Other Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Assets, Other Expected future employer contributions, next fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Amortization of unrealized net (gains)/losses on cash flow hedging activities Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Schedule of Changes in Stock Options Outstanding Share-Based Payment Arrangement, Option, Activity [Table Text Block] Weighted Average Price (in dollars) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Measure: Measure [Axis] Allowance for doubtful accounts SEC Schedule, 12-09, Allowance, Credit Loss [Member] One year to two years Available For Sale Securities Debt Maturities Due After One Year Up To Two Fair Value This item represents the fair value of debt securities which are expected to mature after one year up to two years after the balance sheet date and which are categorized neither as held-to-maturity nor trading securities. Treasury stock, shares Treasury Stock, Common, Shares Schedule of Finite-Lived Intangible Assets Intangible Asset, Finite-Lived, Acquired [Table Text Block] Equity Components [Axis] Equity Components [Axis] Cash paid for income taxes, net of income tax refunds Total income taxes paid Income Tax Paid, after Refund Received Deferred contract costs Capitalized Contract Cost, Net Valuation allowance Less: valuation allowances Deferred Tax Assets, Valuation Allowance Entity Interactive Data Current Entity Interactive Data Current Entity Small Business Entity Small Business Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Tax effect Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Property, Plant, and Equipment [Line Items] Property, Plant, and Equipment [Line Items] Increase/(decrease) in accounts payable Increase (Decrease) in Accounts Payable, Trade MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Nontaxable or nondeductible items Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount Other assets Other Assets, Noncurrent Document Type Document Type Collection period Revenue From Contract With Customer, Collection Period Revenue From Contract With Customer, Collection Period Acquisitions of businesses, net of cash acquired Cash paid for acquisition of business, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Defined benefit plan, accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Reductions for tax positions of prior periods Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Change in benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Time Based Restricted Shares and Units Time Based Restricted Shares And Units [Table Text Block] [Table Text Block] Disclosure of the number for Time-Based restricted stock and Time-Based restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock and restricted stock units that were granted, vested, or forfeited during the year. Options, vested and expected to vest, exercisable, aggregate intrinsic value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Cash and cash equivalents Cash and Cash Equivalents [Member] Currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Proceeds from the issuance of debt Proceeds from Issuance of Long-Term Debt Local Phone Number Local Phone Number Long-term deferred revenues Contract with Customer, Liability, Noncurrent Canada CANADA Deferred tax liabilities Deferred Tax Liabilities, Gross Additions for tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions EARNINGS BEFORE INCOME TAXES Total consolidated earnings before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Commitments and Contingencies (Note 13) Commitments and Contingencies Short-term debt, average outstanding amount Short-Term Debt, Average Outstanding Amount Property, plant and equipment, gross Property, Plant, and Equipment, before Accumulated Depreciation, Depletion, and Amortization Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Excess tax benefit - Stock-based compensation Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-Based Payment Arrangement, Percent Twelve months ending June 30, 2030 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Four Executive Category: Executive Category [Axis] Acquisitions Business Combination [Policy Text Block] Capitalized Contract Cost [Line Items] Capitalized Contract Cost [Line Items] Liabilities and Stockholders' Equity Liabilities and Equity [Abstract] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Schedule of Defined Benefit Plan Target Allocation Percentage Defined Benefit Plan Target Allocation Percentage [Table Text Block] Defined Benefit Plan Target Allocation Percentage [Text Block] Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Stock-based compensation expense Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost PEO Name PEO Name Cash Flow Hedging Activities Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Income taxes paid Income Tax Paid, before Refund Received Other segment expenses Segment Reporting, Other Segment Item, Amount Less: cash acquired Cash Acquired from Acquisition Property, Plant and Equipment, Type [Axis] Long-Lived Asset, Class [Axis] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Notes payable Notes Payable Weighted Average Price, exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Prepaid expenses Deferred Tax Liabilities, Prepaid Expenses Weighted average maturity (approximately in days) Commercial Paper Weight Average Maturity Reflects the calculated weighted average maturity of the Company's commercial paper Interest crediting rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Weighted-Average Interest Crediting Rate Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] 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] Schedule of Investment of Funds Held for Clients Schedule Of Investment Of Funds Held For Clients [Table Text Block] This element represents the carrying amounts of all investments of funds held for clients on the Consolidated Balance Sheets including cash and cash equivalents, short-term and long-term investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. Debt Instrument [Axis] Debt Instrument [Axis] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Total operating lease cost Lease, Cost Employee Stock Employee Stock [Member] BASIC EARNINGS PER SHARE (in dollars per share) Earnings Per Share, Basic Other Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount Total current assets Assets, Current Minimum interest crediting rate Defined Benefit Plan, Assumptions Used, Weighted-Average Interest Crediting Rate, Minimum Defined Benefit Plan, Assumptions Used, Weighted-Average Interest Crediting Rate, Minimum Schedule of Classification of Corporate Investments on the Consolidated Balance Sheets Schedule Of Corporate Investments [Table Text Block] This element represents the carrying amounts of all corporate investments on the Consolidated Balance Sheets including cash and cash equivalents, short-term and long-term investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. This element excludes same type of investments held as funds held for clients which is disclosed in a separate table. Insider Trading Arrangements [Line Items] Long-term debt Total long-term debt Long-Term Debt, Excluding Current Maturities Short-term lease cost Short-Term Lease, Cost Document Annual Report Document Annual Report Accounts receivable, net of allowance for doubtful accounts of $44.5 and $47.1, respectively Accounts Receivable, after Allowance for Credit Loss, Current 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] Impact of foreign exchange rate fluctuations Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation Defined contribution plan, maximum annual contribution per employee, percent Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Auditor Information [Abstract] Auditor Information [Abstract] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover page. Cover [Abstract] Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Equity Awards Adjustments Equity Awards Adjustments [Member] Net amount recognized Defined Benefit Plan, Funded (Unfunded) Status of Plan Extension option term Debt Instrument, Extension Option Term Debt Instrument, Extension Option Term Total current liabilities before client funds obligations Total current liabilities before client funds obligations Total current liabilities before client funds obligations Less: current portion Debt, Current Plan Name [Axis] Plan Name [Axis] Current Current [Member] Current [Member] Income Tax Jurisdiction [Domain] Income Tax Jurisdiction [Domain] Obligations under reverse repurchase agreements Obligations under reverse repurchase agreements Obligations Under Reverse Repurchase Agreements Obligations Under Reverse Repurchase Agreements Twelve months ending June 30, 2031 Intangible Asset, Finite-Lived, Estimated Amortization Expense, Year Five Other securities Other Other Debt Obligations [Member] Net increase/(decrease) in client funds obligations Net Increase (Decrease) In Client Funds Obligations Net (decrease) increase in client funds obligations Reclassification of pension liability adjustment to net earnings Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax Restricted units forfeited Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Other Income, Net [Abstract] Other Income, Net [Abstract] Other Income, net Preferred stock, shares authorized Preferred Stock, Shares Authorized Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Aggregate committed obligations under reverse repurchase agreements Debt Instrument, Aggregate Committed Obligations Under Reverse Repurchase Agreements Debt Instrument, Aggregate Committed Obligations Under Reverse Repurchase Agreements Currency translation adjustments Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss) Commercial Mortgage-Backed Securities Commercial Mortgage-Backed Securities [Member] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Corporate Investments and Funds Held for Clients Investment, Policy [Policy Text Block] Income Tax Jurisdiction [Axis] Income Tax Jurisdiction [Axis] Other Corporate And Reconciling Items [Member] Corporate And Reconciling Items Income Taxes Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Other Other Noncash Income (Expense) Twelve months ending June 30, 2031 Lessee, Operating Lease, Liability, to be Paid, Year Five Schedule of Defined Benefit Plan, Plan With Projected Benefit Obligation in Excess of Plan Assets Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets [Table Text Block] Customer/Partner relationships Customer And Partner Relationships [Member] Customer And Partner Relationships Summary of Income Tax Examinations Summary of Income Tax Examinations [Table Text Block] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Entity Filer Category Entity Filer Category Total, fair market value Debt Securities, Available-for-Sale, Unrealized Loss Position Discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Weighted average interest rates Debt Instrument, Interest Rate During Period SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] PEO Services Peo Services Segment [Member] PEO Services Segment. Client fund obligation repayment period Client Fund Obligation repayment period Period of time from the Balance Sheet Date that client fund obligations has to be repaid Current assets: Assets, Current [Abstract] Senior Notes Senior Notes [Member] Foreign Currency Foreign Currency Transactions and Translations Policy [Policy Text Block] Entity Address, Address Line One Entity Address, Address Line One Operating lease ROU assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Acquired Including Goodwill Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Acquired Including Goodwill Line of credit facility, fair value of amount outstanding Line of Credit Facility, Fair Value of Amount Outstanding Provision for income taxes Total provision for income taxes Income Tax Expense (Benefit) Basis of Preparation Consolidation, Policy [Policy Text Block] Net cash (distributed)/received from the Internal Revenue Service (Payments For) Proceeds From Internal Revenue Service, Net (Payments For) Proceeds From Internal Revenue Service, Net Pension net gains/(losses) arising during the year Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Client funds investments with original maturities Client Funds Investments Original Maturity Period Client funds investments, maturity period. Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Account Classification [Domain] Account Classification [Domain] [Domain] for Account Classification [Axis] Fixed-rate 1.25% notes due September 1, 2030 Notes due on 2030 [Member] Notes due on 2030 Statement [Table] Statement [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Interest income on corporate funds Investment Income, Interest HRO, excluding PEO zero-margin benefits pass-throughs HRO [Member] HRO [Member] Deferred costs, impairment loss Capitalized Contract Cost, Impairment Loss Summary of Contract with Customer, Liability Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Federal Current Federal Tax Expense (Benefit) Global equity securities Global Equity Securities [Member] Global Equity Securities [Domain]