Operating lease liabilities - short-term Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Liability, Current Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Liability, Current Business Acquisition [Axis] Business Acquisition [Axis] Amounts reclassified from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Third Party Third Party [Member] Third Party Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Deferred tax assets Deferred Income Tax Assets, Net Outstanding Balance Long-Term Debt, Gross Financial Standby Letter of Credit Financial Standby Letter of Credit [Member] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Intelligence Clients Intelligence Clients [Member] Intelligence Clients [Member] Debt Instrument [Axis] Debt Instrument [Axis] Revolving credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Debt Debt Instrument, Fair Value Disclosure New Term Loan A New Tranche A Term Loan [Member] New Tranche A Term Loan Long-term deferred compensation plan asset Deferred Compensation Plan Assets Other Interest Income (Expense), Other Interest Income (Expense), Other Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Long-term debt, basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Other investing activities Payments for (Proceeds from) Other Investing Activities Statistical Measurement [Domain] Statistical Measurement [Domain] Stock options exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Debt instrument (as a percent) Debt Instrument, Interest Rate, Stated Percentage Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Other Current Assets Other Current Assets [Member] Additional paid-in capital Additional Paid in Capital, Common Stock Schedule of Business Acquisitions, by Acquisition Schedule of Business Acquisitions, by Acquisition [Table Text Block] Repayments on revolving credit facility, term loans, and Senior Notes Repayments of Debt Variable rate, floor Debt Instrument, Basis Spread on Variable Rate, Floor Debt Instrument, Basis Spread on Variable Rate, Floor Repurchase of common stock Repurchase of common stock, value Treasury Stock, Value, Acquired, Cost Method Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Net income attributable to common stockholders Net Income (Loss) Attributable to Parent Tax Period [Domain] Tax Period [Domain] Equity Component [Domain] Equity Component [Domain] Term Loans Secured Debt [Member] Earnings per common share Earnings Per Share Reconciliation [Abstract] Estimate of possible loss Loss Contingency, Estimate of Possible Loss Secured Credit Facility Secured Credit Facility [Member] Secured Credit Facility Long-term Debt, Current and Noncurrent [Abstract] Long-Term Debt, Current and Noncurrent [Abstract] Related Party [Domain] Related Party [Domain] Treasury stock, at cost — 32,907,013 shares at December 31, 2022 and 31,788,197 shares at March 31, 2022 Treasury Stock, Common, Value Plan Name [Axis] Plan Name [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Net cash paid during the period for: Cash Payments Abstract Cash paid during the period for: Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Derivative Instrument [Axis] Derivative Instrument [Axis] Number of operating segments Number of Operating Segments Plan Name [Domain] Plan Name [Domain] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Revolving credit facility, amount outstanding Long-Term Line of Credit Entity Address, State or Province Entity Address, State or Province Level 1 Fair Value, Inputs, Level 1 [Member] Other comprehensive income, net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Award Type [Axis] Award Type [Axis] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Operating lease liabilities Operating Lease, Liability, Current Derivative asset Derivative Asset Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Proceeds from sale of businesses Proceeds from Divestiture of Businesses Operating costs and expenses: Costs and Expenses [Abstract] Estimate of amount to be reclassified over the next 12 months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Long-term debt, net of current portion Long-Term Debt, Excluding Current Maturities Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] EverWatch Ever Watch [Member] Ever Watch Subcontractor Sales Channel, Through Intermediary [Member] Total liabilities Liabilities Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Geographical [Axis] Geographical [Axis] Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Issuance of common stock Stock Issued During Period, Value, New Issues Current derivative instruments Derivative Liability, Current Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Document Type Document Type SOFR Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Compensation Related Costs [Abstract] Compensation Related Costs [Abstract] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Assets: Assets, Fair Value Disclosure [Abstract] Current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Debt Debt Disclosure [Text Block] Entity Shell Company Entity Shell Company Concentration Risk [Table] Concentration Risk [Table] Disposal group, including discontinued operation, goodwill Disposal Group, Including Discontinued Operation, Goodwill Amount of Pre-Tax Gain or (Loss) Recognized in AOCI on Derivatives Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax New Term Loan A New Term Loan A [Member] New Term Loan A Revenue Benchmark Revenue Benchmark [Member] New Revolving Commitments New Revolving Commitments [Member] New Revolving Commitments Schedule of Contract Assets and Liabilities Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Document Period End Date Document Period End Date Term Loan A Term Loan A [Member] Term Loan A Retirement Plan Name [Domain] Retirement Plan Name [Domain] Total fair value of identifiable net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Schedule of Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Total assets Assets Triggering Event [Axis] Triggering Event [Axis] Triggering Event Debt Disclosure [Abstract] Debt Disclosure [Abstract] Earnings per common share (Note 4): Earnings Per Share [Abstract] Earnings Per Share [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Schedule of Recurring Fair Value Measurements Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Interest Rate Swap Interest income (expense) Interest Rate Swap [Member] Accrued expenses Accrued Liabilities, Current Schedule of Accounts Payable and Accrued Liabilities Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Other comprehensive income (loss) before reclassifications, tax expense Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Current portion of long-term debt Less: Current portion of long-term debt Long-Term Debt, Current Maturities Current assets Contract with Customer, Asset, after Allowance for Credit Loss [Abstract] Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Interest expense on debt Interest Expense, Debt Global Commercial Clients Global Commercial Clients [Member] Global Commercial Clients [Member] Accrued compensation and benefits Total accrued compensation and benefits Employee-related Liabilities, Current Gain on disposition of business Gain (Loss) on Disposition of Business Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Amortization of debt issuance costs and discounts Amortization of debt issuance cost (DIC) and original issue discount (OID) Amortization of Debt Issuance Costs and Discounts Repurchase of shares to cover tax withholding on restricted stock units that vested Repurchase Of Stock To Satisfy Tax Withholdings, Restricted Stock, Amount Repurchase Of Stock To Satisfy Tax Withholdings, Restricted Stock, Amount Earnings Per Share Earnings Per Share [Text Block] Interest payments Interest Paid, Including Capitalized Interest, Operating and Investing Activities Customer [Axis] Customer [Axis] Other Noncurrent Liabilities Other Noncurrent Liabilities [Member] Long-term deferred compensation plan liability Deferred Compensation Liability, Classified, Noncurrent Undistributed earnings allocated to participating securities, diluted Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Disposal Group, Disposed of by Sale, Not Discontinued Operations Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Award Type [Domain] Award Type [Domain] Weighted Average Remaining Period to be Recognized (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Loss on debt extinguishment Gain (Loss) on Extinguishment of Debt Deferred income taxes and income taxes receivable / payable Increase (Decrease) in Income Taxes Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Cash consideration (gross of cash acquired) Payments to Acquire Businesses, Gross Derivative Contract [Domain] Derivative Contract [Domain] Acquisitions, Divestiture and Goodwill Business Combinations, Divestitures And Goodwill Disclosure [Text Block] Business Combinations, Divestitures And Goodwill Disclosure Entity Registrant Name Entity Registrant Name Officer Medical Plan Officer Medical Plan [Member] Officer Medical Plan [Member] Issuance of common stock (in shares) Stock Issued During Period, Shares, New Issues Refund amount Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority Entity Address, City or Town Entity Address, City or Town Employee Benefit Plans Retirement Benefits [Text Block] Derivatives designated as cash flow hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] De-consolidation of non-controlling interest Noncontrolling Interest, Decrease from Deconsolidation Total stockholders’ equity Beginning of period End of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Contract with Customer, Sales Channel [Axis] Contract with Customer, Sales Channel [Axis] Minimum Minimum [Member] Non-controlling interest Stockholders' Equity Attributable to Noncontrolling Interest Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] Amount of Pre-Tax Gain or (Loss) Reclassified from AOCI into Income Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net Debt issuance costs, net Debt Issuance Costs, Net Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Treasury Stock Treasury Stock, Common [Member] Fair Value Measurements Fair Value Disclosures [Text Block] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Trading Symbol Trading Symbol Entity File Number Entity File Number Treasury stock (in shares) Beginning of period (in shares) End of period (in shares) Treasury Stock, Common, Shares Reclassification from AOCI, current period, tax Reclassification from AOCI, Current Period, Tax Vendor payables Accounts Payable, Trade, Current Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Undistributed earnings allocated to participating securities, basic Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Comprehensive loss attributable to non-controlling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Guarantor obligations, reduction to available borrowings Guarantor Obligations, Liquidation Proceeds, Monetary Amount Disposal Group Classification [Axis] Disposal Group Classification [Axis] Restricted stock granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Restricted stock units (RSUs) Restricted Stock Units (RSUs) [Member] Effective income tax rate (as a percent) Effective Income Tax Rate Reconciliation, Percent Proceeds from revolving credit facility Proceeds from Lines of Credit Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Accounting Estimates Use of Estimates, Policy [Policy Text Block] Contractor Concentration Type Risk Contractor Concentration Type Risk [Member] Contractor Concentration Type Risk Concentration risk (as a percent) Concentration Risk, Percentage Change in unrealized gain on derivatives designated as cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Accounts payable and other accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Income Taxes Income Tax Disclosure [Text Block] Credit Facility [Domain] Credit Facility [Domain] Operating lease right-of-use asset Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Right-Of-Use Asset Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease, Right-Of-Use Asset Interest Interest Paid, Excluding Capitalized Interest, Operating Activities Basic (in dollars per share) Earnings Per Share, Basic Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Post-retirement plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Total Booz Allen stockholders' equity Stockholders' Equity Attributable to Parent Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] Before Two Year Anniversary Before Two Year Anniversary [Member] Before Two Year Anniversary Entity Interactive Data Current Entity Interactive Data Current Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Senior Notes due 2029 Senior Notes Due 2029 [Member] Senior Notes Due 2029 Retirement Liability, Pension and Other Postretirement and Postemployment Benefits, Current Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Retained Earnings Retained Earnings [Member] Cash dividends paid Payments of Dividends Common Stock Common Stock [Member] Schedule of Stock-Based Compensation Expense Recognized in the Condensed Consolidated Statements of Operations Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Number of reportable segments Number of Reportable Segments Repurchases of common stock Payments for Repurchase of Common Stock Class of Stock [Axis] Class of Stock [Axis] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Statement [Table] Statement [Table] Interest Rate Debt Instrument, Interest Rate, Effective Percentage Gain associated with equity method investment activities Equity Method Investment, Realized Gain (Loss) on Disposal Document Quarterly Report Document Quarterly Report Letter of Credit Letter of Credit [Member] Current assets: Assets, Current [Abstract] Operating lease liabilities, net of current portion Operating Lease, Liability, Noncurrent Employees’ capital accumulation plan, total expense recognized Defined Contribution Plan, Cost Statistical Measurement [Axis] Statistical Measurement [Axis] Repurchase of common stock (in shares) Repurchase of common stock (in shares) Treasury Stock, Shares, Acquired Accounts receivable–unbilled (contract assets) Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Retained earnings Retained Earnings (Accumulated Deficit) Disposal Group Name [Axis] Disposal Group Name [Axis] Accounts receivable, net Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss, Current Triggering Event [Domain] Triggering Event [Domain] Triggering Event Equity Components [Axis] Equity Components [Axis] MENA Business MENA business [Member] MENA business Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Litigation Case [Domain] Litigation Case [Domain] Schedule of Accrued Compensation and Benefits Schedule of Accrued Compensation And Benefits [Table Text Block] Schedule of Accrued Compensation And Benefits [Table Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Statement [Line Items] Statement [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Variable Rate [Domain] Variable Rate [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Other Other Employee-related Liabilities, Current Loss Contingencies [Table] Loss Contingencies [Table] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Accumulated Other Comprehensive Income (Loss) Totals AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Purchases of property, equipment, and software Payments to Acquire Productive Assets Document Transition Report Document Transition Report Senior Notes due 2028 Senior Notes Due 2028 [Member] Senior Notes Due 2028 Local Phone Number Local Phone Number Operating income Operating Income (Loss) Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Existing Term Loan A Loans Tranche-A Loans [Member] Tranche A Loans [Member] Prepaid expenses and other current and long-term assets Increase (Decrease) in Prepaid Expense and Other Assets Common stock, outstanding (in shares) Beginning of period (in shares) End of period (in shares) Common Stock, Shares, Outstanding U.S. Department of Justice U.S. Department of Justice [Member] U.S. Department of Justice Goodwill Goodwill Goodwill Other Current Liabilities Other Current Liabilities [Member] Contribution to non-controlling interest Noncontrolling Interest, Increase From Contributions Noncontrolling Interest, Increase From Contributions 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] Income tax expense Income Tax Expense (Benefit) Contracts with U.S. government agencies or other U.S. government contractors Government Contracts Concentration Risk [Member] Geographical [Domain] Geographical [Domain] Deferred tax liabilities Deferred Income Tax Liabilities, Net After Two Year But Before Five Year Anniversary After Two Year But Before Five Year Anniversary [Member] After Two Year But Before Five Year Anniversary Income Statement [Abstract] Income Statement [Abstract] Hedging Relationship [Axis] Hedging Relationship [Axis] Additional Paid-In Capital Additional Paid-in Capital [Member] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Cost of revenue Cost of Goods and Services Sold Derivative [Line Items] Derivative [Line Items] Weighted-average common shares outstanding for diluted computations (in shares) Weighted Average Number of Shares Outstanding, Diluted Derivative liability Derivative Liability Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] 4.00% Senior Notes due 2029 4.00% Senior Notes due 2029 [Member] 4.00% Senior Notes due 2029 Accounts receivable–billed Billed Contracts Receivable Loss Contingencies [Line Items] Loss Contingencies [Line Items] Period for post-closing working capital adjustments Business Combination, Period For Post-Closing Working Capital Adjustments Business Combination, Period For Post-Closing Working Capital Adjustments Civil Clients Civil Clients [Member] Civil Clients [Member] Dividends paid (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Base Rate Base Rate [Member] Operating lease liabilities - long-term Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Liability, Noncurrent Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Liability, Noncurrent Accounts payable and other accrued expenses Total accounts payable and other accrued expenses Accounts Payable and Accrued Liabilities, Current Common stock, Class A - $0.01 par value - authorized, 600,000,000 shares; issued, 165,262,848 shares at December 31, 2022 and 164,372,545 shares at March 31, 2022; outstanding, 132,355,835 shares at December 31, 2022 and 132,584,348 shares at March 31, 2022 Common Stock, Value, Issued Carrying Amount Reported Value Measurement [Member] Current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Senior Notes Senior Notes [Member] Prime Contractor Sales Channel, Directly to Consumer [Member] Income tax reserves Liability for Uncertainty in Income Taxes, Noncurrent Variable rate, adjustment Debt Instrument, Basis Spread on Variable Rate, Adjustment Debt Instrument, Basis Spread on Variable Rate, Adjustment Product Concentration Risk Product Concentration Risk [Member] Cash and cash equivalents––beginning of period Cash and cash equivalents––end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Bonus Accrued Bonuses, Current Net loss attributable to non-controlling interest Net Income (Loss) Attributable to Noncontrolling Interest Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Current liabilities: Liabilities, Current [Abstract] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Net proceeds from debt issuance Proceeds from Issuance of Long-Term Debt Stock option exercises Proceeds from Stock Options Exercised Noncash lease expense Noncash Lease Expense Noncash Lease Expense Common stock, issued (in shares) Common Stock, Shares, Issued Concentration Risk [Line Items] Concentration Risk [Line Items] Guarantor obligations, available amount Guarantor Obligations, Available Amount Guarantor Obligations, Available Amount Retirement Plan Type [Domain] Retirement Plan Type [Domain] Income Statement Location [Domain] Income Statement Location [Domain] Cash Flow Hedging Cash Flow Hedging [Member] 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] Amendment Flag Amendment Flag Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Equity Incentive Plan Options Amended and Restated Equity Incentive Plan [Member] Amended and Restated Equity Incentive Plan [Member] Earnings for basic computations Undistributed Earnings, Basic Total other comprehensive (loss) income, net of tax Other comprehensive income, net of tax Other Comprehensive Income (Loss), Net of Tax Comprehensive income attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Guarantor obligations, carrying value Guarantor Obligations, Current Carrying Value Litigation Case [Axis] Litigation Case [Axis] Entity Current Reporting Status Entity Current Reporting Status Other current liabilities Other Liabilities, Current Deferred tax liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Other long-term assets Other Assets, Noncurrent Accrued compensation and benefits Increase (Decrease) in Employee Related Liabilities Depreciation and amortization Depreciation, Depletion and Amortization Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Cost-reimbursable Cost Reimbursable Contract [Member] Cost Reimbursable Contract Derivative [Table] Derivative [Table] Stock options outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Income tax assessments Income Tax Examination, Estimate of Possible Loss Less: Unamortized debt issuance costs and discount on debt Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Schedule of Interest Expense Interest Income and Interest Expense Disclosure [Table Text Block] Restricted Stock and other awards Annual Incentive Plan [Member] Annual Incentive Plan [Member] Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Property and equipment, net of accumulated depreciation Property, Plant and Equipment, Net Equity Incentive Plan Options Share-Based Payment Arrangement, Option [Member] Change in postretirement plan costs Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Dividends Dividends Other current liabilities Contract with Customer, Liability [Abstract] Allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current Fixed-price Fixed-Price Contract [Member] Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Total Long-Term Debt Other income, net Other Nonoperating Income (Expense) Balance Sheet Location [Axis] Balance Sheet Location [Axis] Common stock, authorized (in shares) Common Stock, Shares Authorized Billable expenses Billable Expenses Billable expenses include direct subcontractor expenses, travel expenses, and other expenses incurred to perform on contracts. Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Maximum Maximum [Member] Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Class A Common Stock Common Class A [Member] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Equity securities gains Equity Securities, FV-NI, Gain (Loss) Total current assets Assets, Current Designated as Hedging Instrument Designated as Hedging Instrument [Member] Term Loan B Term Loan B [Member] Term Loan B Income taxes Income Taxes Paid, Net Contract with customer, liability, revenue recognized Contract with Customer, Liability, Revenue Recognized Business Acquisition [Line Items] Business Acquisition [Line Items] Entity Small Business Entity Small Business Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Remaining performance obligation, expected timing, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Existing Term Loan B Loans Tranche B Loans [Member] Tranche B Loans [Member] Unrecognized Compensation Cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Accounts receivable, net Increase (Decrease) in Accounts Receivable Title of 12(b) Security Title of 12(b) Security Total Assets Other Assets, Fair Value Disclosure Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Consolidated Entities [Axis] Consolidated Entities [Axis] Total operating costs and expenses Costs and Expenses Payables and Accruals [Abstract] Payables and Accruals [Abstract] Defense Clients Defense Clients [Member] Defense Clients [Member] Long term derivative instruments Derivative Asset, Noncurrent Debt Instrument [Line Items] Debt Instrument [Line Items] Business Combination and Asset Acquisition [Abstract] Earnings for diluted computations Undistributed Earnings, Diluted LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Estimated Fair Value Estimate of Fair Value Measurement [Member] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] 3.88% Senior Notes due 2028 3.88% Senior Notes due 2028 [Member] 3.88% Senior Notes due 2028 Equity securities, fair value Equity Securities, FV-NI, Cost Number of employees Entity Number of Employees Hedging Relationship [Domain] Hedging Relationship [Domain] Hedging Designation [Axis] Hedging Designation [Axis] Business Overview Nature of Operations [Text Block] Entity Filer Category Entity Filer Category Weighted-average common shares outstanding for basic computations (in shares) Weighted Average Number of Shares Outstanding, Basic Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Total U.S. government UNITED STATES Schedule of Unrecognized Compensation Cost Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Interest Swap Expense Interest Expense, Debt, Interest Swap Interest Expense, Debt, Interest Swap Provision for claimed indirect costs Liability for reductions and/or penalties from U.S Government audits Loss Contingency Accrual Liabilities: Liabilities, Fair Value Disclosure [Abstract] MTS Business MTS Business [Member] MTS Business Stock-based compensation expense Share-Based Payment Arrangement, Expense Commitments and contingencies (Note 15) Commitments and Contingencies Security Exchange Name Security Exchange Name Gain on dispositions, and other Gain (Loss) on Disposition of Assets Useful life (in years) Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Total accounts receivable, net Accounts Receivable, after Allowance for Credit Loss Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Notional amount of interest rate swaps Derivative, Notional Amount Restricted Stock Awards Restricted Stock [Member] Schedule of Debt Schedule of Debt [Table Text Block] General and administrative expenses General and Administrative Expense [Member] Revenue Revenue from Contract with Customer, Excluding Assessed Tax Employer matching contribution, percent of match (as a percent) Defined Contribution Plan, Employer Matching Contribution, Percent of Match Cover [Abstract] Cover [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Level 3 Fair Value, Inputs, Level 3 [Member] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Stock-Based Compensation Share-Based Payment Arrangement [Text Block] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Revenue Revenue from Contract with Customer [Text Block] Overnight Federal Funds Rate Overnight Federal Funds Rate [Member] Overnight Federal Funds Rate Non-Controlling Interest Noncontrolling Interest [Member] Current derivative instruments Derivative Asset, Current Retirement Plan Name [Axis] Retirement Plan Name [Axis] Total liabilities and stockholders’ equity Liabilities and Equity Amortization of debt issuance costs Amortization of Debt Issuance Costs Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Related Party [Axis] Related Party [Axis] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Vacation Accrued Vacation, Current Unvested shares participating in the payment of the company's dividends declared (in shares) Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Disposal Group Name [Domain] Disposal Group Name [Domain] Payments for business acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Level 2 Fair Value, Inputs, Level 2 [Member] Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Payments for cost method investments Payments to Acquire Investments Current Fiscal Year End Date Current Fiscal Year End Date Accounts Payable and Other Accrued Expenses Accounts Payable and Accrued Liabilities Disclosure [Text Block] Diluted (in dollars per share) Earnings Per Share, Diluted Intangible assets, net of accumulated amortization Intangible Assets, Net (Excluding Goodwill) Stock-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Concentration Risk Type [Axis] Concentration Risk Type [Axis] Total current liabilities Liabilities, Current Dividends declared Dividends, Cash Customer Concentration Risk Customer Concentration Risk [Member] Revenue, amount of remaining performance obligation Revenue, Remaining Performance Obligation, Amount Commitment fee (as a percent) Line of Credit Facility, Commitment Fee Percentage Schedule of Derivative Instruments Schedule of Derivative Instruments [Table Text Block] Revenue from Contract with Customer Benchmark Revenue from Contract with Customer Benchmark [Member] Potential future tax expense that would arise Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Entity Address, Address Line One Entity Address, Address Line One Advance payments, billings in excess of costs incurred and deferred revenue (contract liabilities) Contract with Customer, Liability Class of Stock [Domain] Class of Stock [Domain] Other long-term assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Interest expense Total Interest Expense Interest Expense Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Credit Facility [Axis] Credit Facility [Axis] Time-and-materials Time-and-Materials Contract [Member] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Tax Years 2013-2015 Tax Years 2013-2015 [Member] Tax Years 2013-2015 [Member] Equity [Abstract] Equity [Abstract] Purchase price allocation: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract] Entity Tax Identification Number Entity Tax Identification Number Defined benefit plan, unfunded status of plan Defined Benefit Plan, Funded (Unfunded) Status of Plan Unfavorable Regulatory Action Unfavorable Regulatory Action [Member] Other Noncurrent Assets Other Noncurrent Assets [Member] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Accounts receivable–unbilled (contract assets) Contract with Customer, Asset, after Allowance for Credit Loss, Current Consolidated Entities [Domain] Consolidated Entities [Domain] Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Recognition of liability related to future restricted stock units vesting Adjustments To Additional Paid In Capital, Recognition Of Liability Related To Future Restricted Stock Units Vesting Adjustments To Additional Paid In Capital, Recognition Of Liability Related To Future Restricted Stock Units Vesting Dilutive stock options and restricted stock (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Entity Central Index Key Entity Central Index Key Measurement Frequency [Axis] Measurement Frequency [Axis] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Consideration transferred Business Combination, Consideration Transferred Tax Period [Axis] Tax Period [Axis] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] City Area Code City Area Code General and administrative expenses General and Administrative Expense ASSETS Assets [Abstract] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Stock options outstanding, unvested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Number of Shares Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Remaining performance obligation (as a percent) Revenue, Remaining Performance Obligation, Percentage Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Total Liabilities Financial Liabilities Fair Value Disclosure Guarantor obligations, facility Guarantor Obligations, Facility Guarantor Obligations, Facility Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Fair value of options granted Shares Granted, Value, Share-Based Payment Arrangement, before Forfeiture Variable Rate [Axis] Variable Rate [Axis] Other long-term liabilities Other Liabilities, Noncurrent Three-month Term SOFR Three-Month Term Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Three-Month Term Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate Disposal Group Classification [Domain] Disposal Group Classification [Domain] Other current and long-term liabilities Increase (Decrease) in Other Operating Liabilities Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Accrued Compensation and Benefits Compensation Related Costs, General [Text Block] Schedule of Reconciliation of the Income Used to Compute Basic and Diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Cost of revenue Cost of Sales [Member] Customer [Domain] Contract with Customer, Sales Channel [Domain] Other Postretirement Benefits Plan Other Postretirement Benefits Plan [Member] Customer [Domain] Customer [Domain] Long-term derivative instruments Derivative Liability, Noncurrent