Restricted stock units and awards (in shares) Incremental Common Shares Attributable To Restricted Stock Units And Awards Incremental common shares attributable to restricted stock awards. Cash equivalents included in funds held for clients Cash Equivalents Included In Funds Held For Clients Cash equivalents included in funds held for clients. Proceeds from bank debt Proceeds from Long-Term Lines of Credit Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Stock options (in shares) Incremental Common Shares Attributable To Stock Options Incremental common shares attributable to stock options. Statistical Measurement [Domain] Statistical Measurement [Domain] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Cover [Abstract] Cover [Abstract] Net decrease in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Fair market value adjustment Available For Sale Securities Debt Securities Fair Market Value Adjustment Available-for-sale securities, debt securities, fair market value adjustment. Other current liabilities Other Liabilities, Current Funds held for clients Funds Held for Clients Trading Symbol Trading Symbol Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] All Trading Arrangements All Trading Arrangements [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Fair value, asset Derivative Asset, Subject to Master Netting Arrangement, before Offset Client fund obligations Client Fund Obligations Client fund obligations. Non-NEOs Non-NEOs [Member] Schedule of Computation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Performance share units, vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Allowance for doubtful accounts Balance at beginning of period Allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss, Current Pay vs Performance Disclosure [Line Items] Debt Securities, Available for Sale [Roll Forward] Debt Securities, Available for Sale [Roll Forward] Debt Securities, Available for Sale Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount 2022 Credit Facility Credit facilities 2022 Credit Facility [Member] 2022 Credit Facility Unrealized gain (loss) on interest rate swaps, income tax expense (benefit) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Accounts receivable, net Increase (Decrease) in Accounts Receivable Goodwill and other intangible assets, net Intangible Assets, Net (Including Goodwill) Schedule of Changes to the Allowance for Doubtful Accounts on Accounts Receivable Schedule Of Changes In Allowance For Doubtful Accounts [Table Text Block] Schedule of changes in allowance for doubtful accounts. Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Proceeds from exercise of stock options Proceeds from Stock Options Exercised Award Timing Disclosures [Line Items] Change in funds held for clients Increase Decrease In Funds Held For Client Investing Activities Increase (decrease) in funds held for client investing activities. Other Performance Measure, Amount Other Performance Measure, Amount Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments and contingencies. Maximum stock based compensation awards granted under the plan (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Lease liabilities Operating Lease, Liability, Noncurrent Certified Deposits and Other Depository Assets Certified Deposits And Other Depository Assets [Member] Certified deposits and other depository assets. Total non-current assets Assets, Noncurrent Accounting, tax, advisory and consulting Accounting Tax Advisory And Consulting [Member] Accounting, tax, advisory and consulting. Investments, All Other Investments [Abstract] Investments, All Other Investments [Abstract] Plan Name [Domain] Plan Name [Domain] Other non-current assets Other Assets, Noncurrent Entity Tax Identification Number Entity Tax Identification Number Share repurchases (in shares) Treasury Stock, Shares, Acquired Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] ACCOUNTS RECEIVABLE, NET Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Operating Segments Operating Segments [Member] Number of practice groups Number Of Practice Groups Number of practice groups. Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Treasury Shares Treasury Stock, Common [Member] Secured Debt Secured Debt [Member] National Practices National Practices [Member] National practices. Plan Name [Axis] Plan Name [Axis] Equity Components [Axis] Equity Components [Axis] Other current assets Other Assets, Current Award Timing Method Award Timing Method [Text Block] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Fair value at beginning of period Fair value at end of period Available-for-sale debt securities Debt Securities, Available-for-Sale Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Notional amount, asset Derivative Asset, Notional Amount Insider Trading Policies and Procedures [Line Items] Proceeds from sales of divested operations Proceeds from Divestiture of Businesses Use of Estimates Use of Estimates, Policy [Policy Text Block] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Adjustment to Compensation, Amount Adjustment to Compensation Amount Investments [Domain] Investments [Domain] Additional paid in capital Additional Paid in Capital, Common Stock Compensation Amount Outstanding Recovery Compensation Amount Diluted Earnings Per Share, Diluted [Abstract] Business days prior to the date of the agreement Business Acquisition, Business Days Prior To The Date Of The Agreement Business Acquisition, Business Days Prior To The Date Of The Agreement 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] Net unrealized gain on available-for-sale securities, net of taxes Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Entity Small Business Entity Small Business Company Selected Measure Amount Company Selected Measure Amount Maturities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Tabular List, Table Tabular List [Table Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Core benefits and insurance services Core Benefits And Insurance Services [Member] Core benefits and insurance services. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] 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] Contingent purchase price liabilities Business Combination, Contingent Consideration, Liability, Current Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Income taxes payable Accrued Income Taxes, Noncurrent Share based awards excluded from the calculation of diluted earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount CBIZ Operations and a former employee of CBIZ MMP C B I Z Operations And Former Employee Of C B I Z M M P [Member] CBIZ Operations and a former employee of CBIZ MMP Member. Credit Facility [Domain] Credit Facility [Domain] Cash, cash equivalents and restricted cash at beginning of year Cash, cash equivalents and restricted cash at end of period Total cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Weighted average rates Debt, Weighted Average Interest Rate Current assets: Assets, Current [Abstract] Consolidation Items [Axis] Consolidation Items [Axis] Indirect repurchase of shares for minimum tax withholding Payment, Tax Withholding, Share-Based Payment Arrangement Net Income Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Treasury stock, beginning balance (in shares) Treasury stock, ending balance (in shares) Treasury Stock, Common, Shares Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Product and Service [Domain] Product and Service [Domain] Employee Stock Option Share-Based Payment Arrangement, Option [Member] Schedule of Available-for-sale Securities [Table] Debt Securities, Available-for-Sale [Table] Achievement of an earnings per share target Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Percentage Of Target Earnings Per Share Share based compensation arrangement by share based payment award equity instruments other than options percentage of target earnings per share. Exercised or released (in dollars per share) Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Income taxes payable Accrued Income Taxes, Current License bonds outstanding amount License Bonds Outstanding Amount License bonds outstanding. Achievement of total growth in revenue Share Based Compensation Arrangements By Share Based Payment Award Performance Stock Of Total Growth In Revenue Share based compensation arrangements by share based payment award performance stock of total growth in revenue. Security Exchange Name Security Exchange Name Award Type [Axis] Award Type [Axis] Percent of shares deliverable, tranche one Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche One Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche One Basic Earnings Per Share, Basic [Abstract] Property and equipment, net Property, Plant and Equipment, Net Stock options Stock or Unit Option Plan Expense Total liabilities Liabilities Outstanding line of credit Short-Term Debt Comprehensive income: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Percent of shares deliverable, tranche two Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche Two Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche Two Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Schedule of Activities Related to Investments Debt Securities, Available-for-Sale [Table Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Revolving Credit Facility Revolving Credit Facility [Member] Expiration Date Trading Arrangement Expiration Date 2019 Plan Two Thousand Nineteen Stock Omnibus Incentive Plan [Member] Two thousand nineteen stock omnibus incentive plan. Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Restricted Stock Units and Awards, Number of Shares Performance Share Units Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Operating lease liabilities Operating Lease, Liability, Current Total Shareholder Return Amount Total Shareholder Return Amount Common stock, beginning balance (in shares) Common stock, ending balance (in shares) Common Stock, Shares, Issued Contingent purchase price liabilities Contingent Purchase Price Liabilities At Fair Value Contingent purchase price liabilities. Income taxes payable Increase (Decrease) in Income Taxes Payable Entity [Domain] Entity [Domain] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Revolving loan commitment Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Other depository assets Other Assets, Fair Value Disclosure Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Subsequent Event [Line Items] Subsequent Event [Line Items] Stock options exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Debt Instrument [Line Items] Debt Instrument [Line Items] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Business acquisitions and purchases of client lists, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Unaudited Interim Financial Statements Basis of Accounting, Policy [Policy Text Block] Diluted weighted average shares outstanding (in shares) Diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Notional amount, liability Derivative Liability, Notional Amount MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Potential termination fee required to pay if debt financing is not obtained Business Acquisition, Potential Termination Fee Required To Pay If Debt Financing Is Not Obtained Business Acquisition, Potential Termination Fee Required To Pay If Debt Financing Is Not Obtained Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent Interest rate swaps Interest Rate Derivatives, at Fair Value, Net FINANCIAL INSTRUMENTS Financial Instruments Disclosure [Text Block] Litigation Case [Axis] Litigation Case [Axis] Balance Sheet Location [Axis] Statement of Financial Position Location, Balance [Axis] Interest expense Interest Expense, Nonoperating Contingent shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares Outstanding letters of credit Letters of credit outstanding Letters of Credit Outstanding, Amount Contingent Purchase Price Liabilities Contingent Purchase Price Payable [Member] Contingent purchase price payable. Senior Credit Facilities Senior Credit Facilities [Member] Senior Credit Facilities Trade accounts receivable Billed Contracts Receivable Other comprehensive (loss) income, net of tax Other comprehensive income (loss) Total other comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Accounts receivable, net Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Managed networking, hardware services Managed Networking And Hardware Services [Member] Managed networking and hardware services. Other liabilities Increase (Decrease) in Other Operating Liabilities Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Document Fiscal Period Focus Document Fiscal Period Focus All Executive Categories All Executive Categories [Member] Balance Sheet Location [Domain] Statement of Financial Position Location, Balance [Domain] Total accounts receivable Accounts Receivable, before Allowance for Credit Loss, Current Business acquisition, share price (in dollars per share) Business Acquisition, Share Price Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] ASSETS Assets [Abstract] Percent of shares outstanding Business Acquisition, Equity Interest Issued Or Issuable, Shares Deliverable, Percent Of Shares Outstanding Business Acquisition, Equity Interest Issued Or Issuable, Shares Deliverable, Percent Of Shares Outstanding Restricted cash Restricted Cash, Current Document Type Document Type Derivative Contract [Domain] Derivative Contract [Domain] Range of effective rates Debt Instrument, Interest Rate, Effective Percentage Exercisable at end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Exercisable, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Exercisable, Weighted Average Grant Date Fair Value Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Schedule of Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Contingent purchase price liabilities Business Combination, Contingent Consideration, Liability, Noncurrent Benefits and Insurance Services Benefits And Insurance Services [Member] Benefits and insurance services. Exercised or released (in shares) Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Par value of available-for-sale debt securities Debt Securities, Available-for-Sale, Amortized Cost Assets of deferred compensation plan Deferred compensation plan assets Deferred Compensation Plan Assets Subsequent Event [Table] Subsequent Event [Table] Maximum Maximum [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Schedule of Changes in Contingent Purchase Price Consideration Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Accounts payable Accounts Payable, Current Investment Type [Axis] Investment Type [Axis] Accounting Policies [Abstract] Accounting Policies [Abstract] LIABILITIES Liabilities [Abstract] Duration of volume weighted average price of common stock Business Acquisition, Duration Of Volume Weighted Average Price Of Common Stock Business Acquisition, Duration Of Volume Weighted Average Price Of Common Stock Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Current Fiscal Year End Date Current Fiscal Year End Date Non-current assets: Assets, Noncurrent [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] PEO Name PEO Name Percent of shares deliverable, tranche three, number of monthly installments Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche Three, Number Of Monthly Installments Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche Three, Number Of Monthly Installments Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Income before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Award Type [Domain] Award Type [Domain] Name Outstanding Recovery, Individual Name Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Restricted stock units and awards and performance share units (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Non-PEO NEO Non-PEO NEO [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Schedule of Accounts Receivable, Net Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Award Timing Predetermined Award Timing Predetermined [Flag] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Unbilled revenue, at net realizable value Unbilled Receivables, Current New Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Forecast Forecast [Member] Class of Stock [Axis] Class of Stock [Axis] Diluted (in dollars per share) Earnings Per Share, Diluted Name Measure Name Entity Interactive Data Current Entity Interactive Data Current Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Redemptions Proceeds from Sale of Debt Securities, Available-for-Sale Number of business units of the company Number of Operating Segments Description of Business Description Of Business Policy [Policy Text Block] Description Of Business Policy Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Schedule of Restricted Stock Units and Awards Activity and Performance Share Units Activity Share-Based Payment Arrangement, Activity [Table Text Block] Percent of shares deliverable, tranche three Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche Three Business Acquisition, Equity Interest Issued Or Issuable, Percent Of Shares Deliverable, Tranche Three Gain on sale of operations, net Gain on sale of operations, net Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Interest Rate Swap, August 2027 Expiration Interest Rate Swap, August 2027 Expiration [Member] Interest Rate Swap, August 2027 Expiration Income tax expense Income Tax Expense (Benefit) Additions from business acquisitions Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Other (expense) income: Other income (expense): Nonoperating Income (Expense) [Abstract] Corporate and Other Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Revenue Revenue from Contract with Customer, Excluding Assessed Tax Total other (expense) income, net Nonoperating Income (Expense) Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Operating income Operating Income (Loss) Business Acquisition [Line Items] Business Acquisition [Line Items] Total liabilities and stockholders’ equity Liabilities and Equity Other, net Other Operating Activities, Cash Flow Statement SUBSEQUENT EVENTS Subsequent Events [Text Block] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] All Adjustments to Compensation All Adjustments to Compensation [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Accrued personnel costs Employee-related Liabilities, Current Additional shares authorized for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Additional Shares Authorized for Issuance Share-Based Compensation Arrangement by Share-Based Payment Award, Additional Shares Authorized for Issuance Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Legal Entity [Axis] Legal Entity [Axis] Restricted stock units and awards Restricted Stock Units and Awards Restricted Stock Units And Awards [Member] Restricted stock units and awards. Underlying Security Market Price Change Underlying Security Market Price Change, Percent Scenario [Domain] Scenario [Domain] Individual: Individual [Axis] Indirect repurchase of shares for minimum tax withholding Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Restricted cash Restricted Cash Product and Service [Axis] Product and Service [Axis] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Entity Address, State or Province Entity Address, State or Province Statement [Line Items] Statement [Line Items] Unrealized gain (loss) on available-for-sale securities, income tax expense OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax Performance share units (in shares) Incremental Common Shares Attributable to Performance Share Incremental common shares attributable to Performance Share Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Marcum Marcum [Member] Marcum Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Total recorded purchase price Aggregate consideration Business Combination, Consideration Transferred Outstanding at beginning of period (in dollars per share) Outstanding at end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Number of claims filed Loss Contingency, New Claims Filed, Number Interest rate swap, fixed interest rate Derivative, Fixed Interest Rate Minimum Minimum [Member] Restatement Determination Date Restatement Determination Date Cash settlement paid Payments for Previous Acquisition Debt issuance costs Unamortized Debt Issuance Expense Adoption Date Trading Arrangement Adoption Date Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Number of defendants Loss Contingency, Number of Defendants Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Dilutive securities included and antidilutive securities excluded from computation of earnings per share. Right-of-use assets, net Operating Lease, Right-of-Use Asset Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Provision Accounts Receivable, Credit Loss Expense (Reversal) Segments [Axis] Segments [Axis] Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Annualized revenue Business Acquisition, Pro Forma Revenue Derivative Instrument [Axis] Derivative Instrument [Axis] Exercise Price Award Exercise Price EARNINGS PER SHARE Earnings Per Share [Text Block] Accrued personnel costs Increase (Decrease) in Employee Related Liabilities Arrangement Duration Trading Arrangement Duration Schedule of Other Comprehensive (Loss) Income and Tax Impact Comprehensive Income (Loss) [Table Text Block] Subsequent Event Subsequent Event [Member] Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Basic earnings per share (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share STOCKHOLDERS' EQUITY Equity, Attributable to Parent [Abstract] Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Segments [Domain] Segments [Domain] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Debt instrument, term Debt Instrument, Term Excise tax on share repurchases Share Repurchase Program, Excise Tax All Individuals All Individuals [Member] Schedule of Effects of Interest Rate Swap Summary Of Effects Of Interest Rate Swaps [Table Text Block] Summary Of Effects Of Interest Rate Swaps Current assets before funds held for clients Current Assets Before Funds Held For Clients Current assets before funds held for clients. PEO PEO [Member] Name Trading Arrangement, Individual Name Other income, net Other Nonoperating Income (Expense) Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Receivables [Abstract] Receivables [Abstract] Schedule of Unsecured Credit Facility Schedule of Line of Credit Facilities [Table Text Block] Treasury stock Treasury Stock, Common, Value Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] 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] Total non-current liabilities Liabilities, Noncurrent Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Total transaction price Transaction Price Transaction price. Local Phone Number Local Phone Number Liability Class [Axis] Liability Class [Axis] Bad debt expense, net of recoveries Provision For Doubtful Accounts Net Of Recoveries Provision for doubtful accounts net of recoveries. Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments and contingencies. Deferred income taxes, net Deferred Income Tax Liabilities, Net Net expense Business Combination Contingent Consideration Liability Other Adjustments Based On Projected Future Results Of Acquisition Business combination contingent consideration liability other adjustments based on projected future results of acquisition. Other assets Increase (Decrease) in Other Operating Assets Changes in assets and liabilities, net of acquisitions and divestitures: Increase (Decrease) in Operating Capital [Abstract] Non-current liabilities: Liabilities, Noncurrent [Abstract] PEO Total Compensation Amount PEO Total Compensation Amount Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Schedule of Recognized Interest Expense Interest Expense Table [Table Text Block] Cash and non-cash interest expense related to the Convertible Notes for the periods presented. Common stock issued (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Fair value, liability Derivative Liability, Subject to Master Netting Arrangement, before Offset Payment of contingent consideration for acquisitions and client lists Payment Of Contingent Consideration Of Acquisitions Payment of contingent consideration for acquisitions. COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Common Stock Common Stock [Member] Measure: Measure [Axis] Restricted stock units and awards and performance share units Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Change in Level 3 Fair Values of Contingent Purchase Price Liabilities Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Other line of credit Line of Credit Line of Credit [Member] Entity Emerging Growth Company Entity Emerging Growth Company Deferred compensation plan obligations Deferred compensation plan liabilities Deferred Compensation Liability, Classified, Noncurrent Segment Reporting [Abstract] Segment Reporting [Abstract] Indirect repurchase of shares for minimum tax withholding (in shares) Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Entity Central Index Key Entity Central Index Key Scenario [Axis] Scenario [Axis] Amount of damages sought (up to) Loss Contingency, Damages Sought, Value Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Changes in Accounting Policies Changes In Accounting Policy [Policy Text Block] Changes In Accounting Policy Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Equity Component [Domain] Equity Component [Domain] SEGMENT DISCLOSURES Segment Reporting Disclosure [Text Block] Financial Services Financial Services [Member] Financial services. Change in fair value of contingencies Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] NEW ACCOUNTING PRONOUNCEMENTS Accounting Standards Update and Change in Accounting Principle [Text Block] Adjustment to contingent earnout liability Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Entity Shell Company Entity Shell Company Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Title Trading Arrangement, Individual Title MOVEit Customer Data Security Breach Litigation MOVEit Customer Data Security Breach Litigation [Member] MOVEit Customer Data Security Breach Litigation Statement [Table] Statement [Table] Total Interest expense Interest Expense, Debt Shares issued (number) Number Of Common Shares Issued Number of common shares issued. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Consolidation Items [Domain] Consolidation Items [Domain] City Area Code City Area Code Current liabilities: Liabilities, Current [Abstract] Charge-offs, net of recoveries Allowance For Doubtful Accounts Receivable Write Offs And Net Of Recoveries Allowance for doubtful accounts receivable write offs and net of recoveries. Recorded contingent consideration Business Combination, Contingent Consideration, Liability Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Potential termination fee required to pay if stockholders do not approve transaction Business Acquisition, Potential Termination Fee Required To Pay If Company's Stockholders Do Not Approve Transaction Business Acquisition, Potential Termination Fee Required To Pay If Company's Stockholders Do Not Approve Transaction Level 1 Fair Value, Inputs, Level 1 [Member] Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Available funds under credit facility Line of Credit Facility, Remaining Borrowing Capacity Payment for acquisition of treasury stock Payments for Repurchase of Common Stock Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Total long-term debt, net Long-Term Debt, Excluding Current Maturities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Restricted Stock Units and Awards, Weighted Average Grant-Date Fair Value Weighted Average Grant-Date Fair Value Per Unit Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Earnings per share: Earnings Per Share [Abstract] Numerator: Net Income (Loss) Attributable to Parent [Abstract] Equity [Abstract] Equity [Abstract] Retained earnings Retained Earnings (Accumulated Deficit) Class of Stock [Domain] Class of Stock [Domain] Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Dilutive securities included and antidilutive securities excluded from computation of earnings per share. Payment of bank debt Repayments of Long-Term Lines of Credit Corporate general and administrative expenses Corporate general and administrative expenses General and Administrative Expense Deferred income taxes Deferred Income Taxes and Tax Credits Other non-current liability Other Noncurrent Liabilities [Member] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Underlying Securities Award Underlying Securities Amount Performance Share Units PSU Performance Shares [Member] Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Abstract] Credit Facility [Axis] Credit Facility [Axis] Amendment Flag Amendment Flag Entity Registrant Name Entity Registrant Name Cash paid Payments to Acquire Businesses, Gross Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Depreciation and amortization expense Depreciation, Depletion and Amortization Gross margin Gross Profit Foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Fair Value as of Grant Date Award Grant Date Fair Value Subsequent Events [Abstract] Level 2 Fair Value, Inputs, Level 2 [Member] DEBT AND FINANCING ARRANGEMENTS Debt Disclosure [Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Schedule of Disaggregation of Revenue by Source Disaggregation of Revenue [Table Text Block] Settlement of contingent purchase price liabilities Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Entity Address, Postal Zip Code Entity Address, Postal Zip Code Schedule of Compensation Expense for Stock-Based Awards Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Basis of Consolidation Consolidation, Policy [Policy Text Block] Interest rate swaps Interest Rate Swap [Member] Restatement Determination Date: Restatement Determination Date [Axis] Title of 12(b) Security Title of 12(b) Security Common stock Common Stock, Value, Issued Current liabilities before client fund obligations Current Liabilities Before Client Fund Obligations Current liabilities before client fund obligations. Other Other Interest Expense [Member] Other interest expense. Restricted stock units and awards Restricted Stock or Unit Expense Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Business acquisitions Stock Issued During Period, Value, Acquisitions Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Interest Rate Swap, October 2028 Expiration Interest Rate Swap, October 2028 Expiration [Member] Interest Rate Swap, October 2028 Expiration Other, net Payments for (Proceeds from) Other Investing Activities Business acquisitions (in shares) Stock Issued During Period, Shares, Acquisitions Other non-current asset Other Noncurrent Assets [Member] 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] Changes in client funds obligations Net Increase Decrease In Client Funds Obligations Net (decrease) increase in client funds obligations. Expired or canceled (in dollars per share) Canceled (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Bank debt Outstanding balance under applicable credit facility Bank debt Long-Term Line of Credit, Noncurrent Proceeds from the sales and maturities of client fund investments Proceeds from Sale, Maturity and Collection of Investments Share-based Payment Arrangement Share-Based Payment Arrangement [Member] Basic (in dollars per share) Earnings Per Share, Basic Accounts payable Increase (Decrease) in Accounts Payable Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Interest Rate Swap, April 2025 Expiration Interest Rate Swap, April 2025 Expiration [Member] Interest Rate Swap, April 2025 Expiration National practices consulting National Practices Consulting [Member] National practices consulting. Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Share-based compensation arrangement by share-based payment award, remaining contractual term Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms Interest Rate Swap, April 2028 Expiration Interest Rate Swap, April 2028 Expiration [Member] Interest Rate Swap, April 2028 Expiration Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Total current liabilities Liabilities, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Denominator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Total assets Assets Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Reconciliation of cash, cash equivalents and restricted cash to the Condensed Consolidated Balance Sheets: Reconciliation Of Cash Cash Equivalents And Restricted Cash To Consolidated Balance Sheet [Abstract] Reconciliation of cash, cash equivalents and restricted cash to the Consolidated Balance Sheets. Additions to property and equipment Payments to Acquire Property, Plant, and Equipment Other non-current liabilities Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Potential termination fee required to pay if approval of partners is not obtained Business Acquisition, Potential Termination Fee Required To Pay If Approval Of Partners Is Not Obtained Business Acquisition, Potential Termination Fee Required To Pay If Approval Of Partners Is Not Obtained Termination Date Trading Arrangement Termination Date Percentage of initial grant Share Based Compensation Arrangements By Share Based Payment Award Performance Stock Percentage Of Initial Grant Share based compensation arrangements by share based payment award performance stock percentage of initial grant. Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] EMPLOYEE STOCK PLANS Share-Based Payment Arrangement [Text Block] Change in bond premium Increase Decrease In Bond Premium Increase (Decrease) in bond premium. Entity Address, City or Town Entity Address, City or Town Debt Instrument [Axis] Debt Instrument [Axis] Total stock-based compensation expense Share-Based Payment Arrangement, Expense Net Income Net income Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] OTHER COMPREHENSIVE INCOME Comprehensive Income (Loss) Note [Text Block] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Expired or canceled (in shares) Canceled (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Business Acquisition [Axis] Business Acquisition [Axis] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Entity File Number Entity File Number Document Fiscal Year Focus Document Fiscal Year Focus Entity Address, Address Line One Entity Address, Address Line One Share repurchases Treasury Stock, Value, Acquired, Cost Method Entity Address, Address Line Two Entity Address, Address Line Two Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Name Forgone Recovery, Individual Name Performance share units Performance Share Units Performance share units. Document Period End Date Document Period End Date Schedule of Outstanding Interest Rate Swaps Schedule of Interest Rate Derivatives [Table Text Block] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Outstanding at beginning of period (in shares) Outstanding at end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Insider Trading Arrangements [Line Items] Stock-based compensation APIC, Share-Based Payment Arrangement, ESPP, Increase for Cost Recognition Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Other current asset Other Current Assets [Member] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Diluted earnings per share (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Operating expenses Operating expenses (income) Cost of Revenue Adjustment to Compensation: Adjustment to Compensation [Axis] Document Transition Report Document Transition Report Document Quarterly Report Document Quarterly Report Gain Reclassified from AOCI into Expense Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Litigation Case [Domain] Litigation Case [Domain] EBK and ComputData EBK and ComputData [Member] EBK and ComputData Non-core benefits and insurance services Non Core Benefits And Insurance Services [Member] Non core benefits and insurance services. Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Current Reporting Status Entity Current Reporting Status Retained Earnings Retained Earnings [Member] Exercisable at end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Exercisable Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Interest Rate Swap, December 2026 Expiration Interest Rate Swap, December 2026 Expiration [Member] Interest Rate Swap, December 2026 Expiration Basic weighted average shares outstanding (in shares) Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Change in net present value of contingencies Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Change In Net Present Value Of Contingencies Fair value measurement with unobservable inputs reconciliation recurring basis liability change in net present value of contingencies. Purchases of client fund investments Payments to Acquire Investments Name Awards Close in Time to MNPI Disclosures, Individual Name Litigation settlement, amount awarded Litigation Settlement, Amount Awarded from Other Party Entity Filer Category Entity Filer Category Purchases Payments to Acquire Debt Securities, Available-for-Sale Gain Recognized in AOCI, net of tax Net unrealized (loss) gain on interest rate swaps, net of taxes Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Company Selected Measure Name Company Selected Measure Name