Revenue from Contract with Customer [Abstract] Contract assets increased due to recognition of revenue related to satisfaction of performance obligations Contract with Customer, Asset, Increase (Decrease) for Contract Acquired in Business Combination Advance contract payments Contract With Customer, Asset, Advanced Contract Payments Contract With Customer, Asset, Advanced Contract Payments Contract liabilities increased due to revenue recognized in excess of payments received Contract with Customer, Liability, Increase (Decrease) for Contract Acquired in Business Combination Amount of contract liabilities recognized as revenue Contract with Customer, Liability, Revenue Recognized Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Performance-based Restricted Stock Units (PSUs) Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding as beginning of year (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number DXC awards replaced by Perspecta awards due to Spin-Off (in shares) Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Previous Awards Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Previous Awards Perspecta awards replacing DXC awards due to Spin-Off (in shares) Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Awards Replaced Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Awards Replaced Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested(in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding at end of year (in shares) Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding as beginning of year (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 DXC awards replaced by Perspecta awards due to Spin-Off (in shares) Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Previous Awards, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Previous Awards, Weighted Average Grant Date Fair Value Perspecta awards replacing DXC awards due to Spin-Off (in shares) Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Awards Replaced, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Awards Replaced, Weighted Average Grant Date Fair Value 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 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 Forfeited (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 Outstanding at end of year (in dollars per share) Restructuring Costs [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Workforce reductions Employee Severance [Member] Facilities costs Facility Closing [Member] Restructuring Plan [Axis] Restructuring Plan [Axis] Restructuring Plan [Domain] Restructuring Plan [Domain] Fiscal 2019 Plan Restructuring Plan Fiscal 2019 Plan [Member] Restructuring Plan Fiscal 2019 Plan [Member] Fiscal 2018 Plan Restructuring Plan Fiscal 2018 Plan [Member] Restructuring Plan Fiscal 2018 Plan [Member] Fiscal 2017 Plan Restructuring Plan Fiscal 2017 Plan [Member] Restructuring Plan Fiscal 2017 Plan [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Restructuring Liability, beginning balance Restructuring Reserve Costs Expensed Restructuring Charges, Reversal Restructuring Charges, Reversal Cash Paid Payments for Restructuring Restructuring Liability, ending balance Income Tax Disclosure [Abstract] Deferred tax assets: Components of Deferred Tax Assets [Abstract] Loss carryovers Deferred Tax Assets, Operating Loss Carryforwards Employee benefits Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits Accrued liabilities Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Capital lease obligations Deferred Tax Assets, Contract Accounting Deferred Tax Assets, Contract Accounting Interest expense carryforward Deferred Tax Assets Accrued Interest The amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis and the book basis of accrued interest computed in accordance with generally accepted accounting principles. The difference in basis, will change future taxable income when such basis difference is realized. Deferred service revenue Deferred Tax Assets, Deferred Income Restructuring Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Restructuring Charges Other Deferred Tax Assets, Other Deferred tax assets, gross Deferred Tax Assets, Gross Valuation allowance Deferred Tax Assets, Valuation Allowance Deferred tax assets, net of valuation allowance Deferred Tax Assets, Net of Valuation Allowance Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Purchased intangible assets Deferred Tax Liabilities, Intangible Assets Fixed assets Deferred Tax Liabilities, Property, Plant and Equipment Deferred service cost Deferred Tax Liabilities, Deferred Expense Other receivables Deferred Tax Liabilities, Other Deferred tax liabilities Deferred Tax Liabilities, Gross Total deferred tax liabilities Deferred Tax Liabilities, Net Retirement Benefits [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Real Estate Funds Defined Benefit Plan, Real Estate [Member] Hedge Funds Hedge Funds [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] Fair value of plan assets at beginning of year Defined Benefit Plan, Plan Assets, Amount Assets assumed as a result of the Mergers Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) For Assets Assumed As A Result Of Business Combination Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) For Assets Assumed As A Result Of Business Combination Actual return on plan assets held at the reporting date Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held Purchases, sales, and settlements Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchase, Sale, and Settlement Fair value of plan assets at end of year Restructuring Restructuring and Related Activities Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments [Table] Other Commitments [Table] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Pending litigation Pending Litigation [Member] Settled litigation Settled Litigation [Member] Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] United States Department Of The Navy v. HP Enterprise Services, LLC United States Department Of The Navy v. HP Enterprise Services, LLC [Member] United States Department Of The Navy v. HP Enterprise Services, LLC [Member] Forsyth, et al. v. HP Inc and Hewlett Packard Enterprice Forsyth, et al. v. HP Inc and Hewlett Packard Enterprice [Member] Forsyth, et al. v. HP Inc and Hewlett Packard Enterprice [Member] Commitments [Line Items] Loss Contingencies [Line Items] Number of individuals deceased Number Of Individuals Deceased In Incident Number Of Individuals Deceased In Incident Number of lawsuits Number Of Lawsuits Number Of Lawsuits Age of plaintiff at time of termination Loss Contingency, Age of Plaintiffs At Time Of Termination Loss Contingency, Age of Plaintiffs At Time Of Termination Number of plaintiffs Loss Contingency, Number of Plaintiffs Accounting Policies [Abstract] Schedule of Revenue and Income Before Tax Schedule Of Revenue And Income Before Tax [Table Text Block] Schedule Of Revenue And Income Before Tax [Table Text Block] Property and Equipment Property, Plant and Equipment [Table Text Block] Schedule of Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of New Accounting Pronouncements and Changes in Accounting Principles Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive income (loss), net of taxes: Other Comprehensive Income (Loss), Net of Tax [Abstract] Cash flow hedge adjustment, net of tax benefit of $8, $0, $0 and $0 Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at beginning of fiscal year Unrecognized Tax Benefits Decrease for transfers to Parent Unrecognized Tax Benefits, Decrease Resulting from Acquisition Increase for transfers from Parent Unrecognized Tax Benefits, Increase Resulting from Acquisition Increase for current year tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Balance at end of fiscal year Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2018 Employee Equity Plan Employee Equity Plan 2018 [Member] Employee Equity Plan 2018 [Member] 2018 Director Equity Plan Director Equity Plan 2018 [Member] Director Equity Plan 2018 [Member] Principal Equity Plan Principal Equity Plan [Member] Principal Equity Plan [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Stock Options Employee Stock Option [Member] Term of incentive plan Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award Aggregate amount of common stock granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Maximum aggregate amount of shares to be issued (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Vesting period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Incremental stock compensation expense as a result of modification of equity awards Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost Cash received from stock awards exercised during the period Proceeds from Stock Options Exercised Total grant date fair value of restricted stock unit awards vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Unrecognized compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Recognition period for compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Performance period Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Period Share-Based Compensation Arrangement By Share-Based Payment Award, Performance Period Intrinsic value of options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating segments Operating Segments [Member] Corporate Corporate, Non-Segment [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Defense and Intelligence Defense And Intelligence Segment [Member] Defense And Intelligence Segment [Member] Civilian and Health Care Civilian And Health Care Segment [Member] Civilian And Health Care Segment [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Series of Individually Immaterial Business Acquisitions Series of Individually Immaterial Business Acquisitions [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of reportable segments Number of Reportable Segments Revenue Revenue from Contract with Customer, Excluding Assessed Tax Segment Profit Operating Income (Loss) Depreciation and Amortization Depreciation, Depletion and Amortization, Nonproduction Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Management Management [Member] Retirement Plan Name [Axis] Retirement Plan Name [Axis] Retirement Plan Name [Domain] Retirement Plan Name [Domain] Enterprise Services LLC Deferred Compensation Plan Enterprise Services LLC Deferred Compensation Plan [Member] Enterprise Services LLC Deferred Compensation Plan [Member] Net projected benefit obligations Defined Benefit Plan, Benefit Obligation Net projected assets Other assets Assets for Plan Benefits, Defined Benefit Plan Other long-term liabilities Liability, Defined Benefit Plan, Noncurrent Defined contribution plan expense Defined Contribution Plan, Cost Percentage of eligible deferred cash compensation Deferred Compensation Arrangement with Individual, Cash Awards Granted, Percentage Deferred compensation liability included in other long-term liabilities Deferred Compensation Liability, Current Overview and Summary of Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Revenue expected to be recognized Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, remaining performance obligation, percent Revenue, Remaining Performance Obligation, Percentage Period to recognize revenue Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Equity [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Program assets Program Assets [Member] Program assets [Member] Developed technology Developed Technology Rights [Member] Backlog Order or Production Backlog [Member] Favorable leases Above Market Leases [Member] Vencore Vencore Holding Corp [Member] Vencore Holding Corp [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Fair Value Finite-lived Intangible Assets Acquired Weighted-average Amortization Period (in years) Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] RSUs Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Changes in the carrying amount of goodwill by segment [Roll Forward] Goodwill [Roll Forward] Goodwill, net, beginning of period Goodwill Additions Goodwill, Acquired During Period Goodwill, net, end of period Receivables [Abstract] Schedule of Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Defined Benefit Pension Plan Pension Plan [Member] Retiree Medical Plan Postretirement Health Coverage [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Projected benefit obligation at beginning of year Benefit obligation assumed as a result of the Mergers Defined Benefit Plan, Benefit Obligation, Business Combination Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Actuarial loss (gain) Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Plan participant contributions Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant Actual benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Projected benefit obligation at end of year Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Assets assumed as a result of the Mergers Defined Benefit Plan, Plan Assets, Business Combination Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Plan participant contributions Defined Benefit Plan, Plan Assets, Contributions by Plan Participant Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Funded status at end of year Defined Benefit Plan, Funded (Unfunded) Status of Plan Stock-based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Segment Information Segment Reporting Disclosure [Text Block] Restructuring costs Restructuring Charges Acquired deferred costs Restructuring Charges, Deferred Restructuring Charges, Deferred Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Program assets Customer-Related Intangible Assets [Member] Software Computer Software, Intangible Asset [Member] Outsourcing contract costs Outsourcing Contract Costs [Member] Costs incurred upon initiation of an outsourcing contract that are deferred and expensed over the contract life. These costs represent incremental external costs or certain specific internal costs that are directly related to the contract acquisition or transition activities. The primary types of costs that may be capitalized include labor and related fringe benefits, subcontractor costs, travel costs, and premiums on asset purchases. Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Gross Carrying Value Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Value Finite-Lived Intangible Assets, Net Schedule of Restructuring Liability Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Vencore and KeyPoint Vencore Holding Corp. and KGS Holding Corp. [Member] Vencore Holding Corp. and KGS Holding Corp. [Member] Payments to acquire business Payments to Acquire Businesses, Gross Shares issued in a business acquisition as a percentage of outstanding shares Business Acquisition, Equity Interest Issued or Issuable, Percentage Of Number of Shares Outstanding Business Acquisition, Equity Interest Issued or Issuable, Percentage Of Number of Shares Outstanding Schedule of Defined Benefit Plans Schedule of Defined Benefit Plans Disclosures [Table Text Block] Schedule of Amounts Recognized on Balance Sheet for Pension Plan Liabilities Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Schedule of Weighted-Average Rates Used to Determine Benefit Obligation Schedule of Assumptions Used [Table Text Block] Schedule of Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Schedule of Fair Value of Financial Assets for Pension and Postretirement Benefits Schedule Of Fair Value Of Financial Assets For Pension And Postretirement Benefits [Table Text Block] Schedule Of Fair Value Of Financial Assets For Pension And Postretirement Benefits [Table Text Block] Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan [Table Text Block] Expected Future Contributions and Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Quarterly Financial Information Disclosure [Abstract] Costs of services Cost of Services, Excluding Depreciation, Depletion, and Amortization Selling, general and administrative Selling, General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization Separation and integration-related costs Separation And Integration Costs Separation And Integration Costs Interest expense, net Interest Expense Other expense, net Other Operating Income (Expense), Net Total costs and expenses Operating Expenses Income before taxes Income (Loss) Attributable to Parent, before Tax Income tax expense (benefit) Income Tax Expense (Benefit) Net income Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Cash dividends per common share (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Weighted average common shares outstanding for basic EPS (in shares) Weighted Average Number of Shares Outstanding, Basic Amortization expense Amortization of Intangible Assets Property, Plant and Equipment [Abstract] Derivative [Table] Derivative [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as hedging instrument Designated as Hedging Instrument [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash flow hedging Cash Flow Hedging [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swap Interest Rate Swap [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest expense Interest Expense [Member] Derivative [Line Items] Derivative [Line Items] Derivative notional amount Derivative Asset, Notional Amount Gain on cash flow hedge ineffectiveness Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Pre-tax impact of gain (loss) on derivatives Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax Cash flow hedge adjustment, net of tax Foreign currency cash flow hedge gain to be reclassified during next 12 months Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months Debt Disclosure [Abstract] Long-term Debt, Fiscal Year Maturity [Abstract] Long-term Debt, Fiscal Year Maturity [Abstract] 2020 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2021 Long-term Debt, Maturities, Repayments of Principal in Year Two 2022 Long-term Debt, Maturities, Repayments of Principal in Year Three 2023 Long-term Debt, Maturities, Repayments of Principal in Year Four 2024 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Total Long-term Debt Noncontrolling Interest [Table] Noncontrolling Interest [Table] Equity Interest Type [Axis] Equity Interest Type [Axis] Equity Interest Issued or Issuable, Type [Domain] Equity Interest Issued or Issuable, Type [Domain] USPS United States Public Sector [Member] United States Public Sector [Member] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Income before taxes Cash and cash equivalents Cash and Cash Equivalents [Member] Equity funds Equity Funds [Member] Fixed income Fixed Income Funds [Member] Real estate funds Real Estate Funds [Member] Hedge funds Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Total investments measured at fair value Total investments measured at NAV Defined Benefit Plan, Plan Assets, Amount, Excluding Net Asset Value Investments Defined Benefit Plan, Plan Assets, Amount, Excluding Net Asset Value Investments [Member] Total investments Defined Benefit Plan, Alternative Investments, Plan Assets, Amount Defined Benefit Plan, Alternative Investments, Plan Assets, Amount Leases [Abstract] Capital lease obligations Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Increase in capital leases obligations Fresh-Start Adjustment, Increase (Decrease), Current Maturities of Capital Lease Obligations Increase to property and equipment Property, Plant and Equipment, Gross, Period Increase (Decrease) Increase to intangible assets Increase (Decrease) in Intangible Assets, Current Interest expense on capital leases Capital Leases, Income Statement, Interest Expense Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale, Name [Domain] Long Lived Assets Held-for-sale, Name [Domain] Land, buildings and leasehold improvements Land, Buildings and Improvements [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Asset held for sale Assets Held-for-sale, Long Lived, Fair Value Disclosure Fair Value Disclosures [Abstract] Fair Value Fair Value Disclosures [Text Block] Intangible Assets Intangible Assets Disclosure [Text Block] Debt Debt Disclosure [Text Block] Hewlett Packard Enterprise Services Hewlett Packard Enterprise Services [Member] Hewlett Packard Enterprise Services [Member] Cash and cash equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Prepaid expenses Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other Total current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Current capital lease obligations, accounts payable, accrued payroll, accrued expenses, and other current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable, and Accrued Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable, and Accrued Liabilities Deferred revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue Non-current capital lease liability Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Capital Lease Obligation Non-current deferred tax liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities And Income Taxes Payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities And Income Taxes Payable Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Total liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Net identifiable assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Goodwill Total estimated consideration transferred Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest Pension and Other Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Capital Leases Leases of Lessee Disclosure [Text Block] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Nonrecurring Adjustment [Axis] Nonrecurring Adjustment [Axis] Nonrecurring Adjustment [Domain] Nonrecurring Adjustment [Domain] Effects of the Spin-Off Adjustment To Interest Expense [Member] Adjustment To Interest Expense [Member] Effects of the Mergers Amortization Expense [Member] Amortization Expense [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Pro Forma Combined for the Spin-Off and Mergers Pro Forma [Member] Business Acquisition, Pro Forma Information [Abstract] Business Acquisition, Pro Forma Information [Abstract] Net income (loss) Earnings per common share Number of shares from distribution in a spinoff (in shares) Weighted average common shares outstanding for diluted EPS (in shares) Weighted Average Number of Shares Outstanding, Diluted 2020 Capital Leases, Future Minimum Payments, Remainder of Fiscal Year 2021 Capital Leases, Future Minimum Payments Due in Two Years 2022 Capital Leases, Future Minimum Payments Due in Three Years 2023 Capital Leases, Future Minimum Payments Due in Four Years 2024 Capital Leases, Future Minimum Payments Due in Five Years Total minimum lease payments Capital Leases, Future Minimum Payments Due Less: amount representing interest and executory costs Capital Leases, Future Minimum Payments, Interest Included in Payments Present value of net minimum lease payments Less: current capital lease liability Capital Lease Obligations, Current Non-current capital lease liability Capital Lease Obligations, Noncurrent Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Current Federal Tax Expense (Benefit) Deferred Current State and Local Tax Expense (Benefit) Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Deferred Federal Income Tax Expense (Benefit) Deferred Deferred State and Local Income Tax Expense (Benefit) Total income tax expense (benefit) Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Term Loan A Term Loan A [Member] Term Loan A [Member] Term Loan B Facility Term Loan B, Due 2025 [Member] Term Loan B, Due 2025 [Member] Term Loan A and B Facilities Term Loan A and B Facilities [Member] Term Loan A and B Facilities [Member] Revolving Credit Facility Revolving Credit Facility, Due 2023 [Member] Revolving Credit Facility, Due 2023 [Member] Revolving Credit Facility and Term Loan A Revolving Credit Facility And Term Loan A [Member] Revolving Credit Facility And Term Loan A [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Secured debt Secured Debt [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] DXC Stockholders DXC Stockholders [Member] DXC Stockholders [Member] Debt Covenant Period [Axis] Debt Covenant Period [Axis] Debt Covenant Period [Axis] Debt Covenant Period [Domain] Debt Covenant Period [Domain] [Domain] for Debt Covenant Period [Axis] On or after September 30, 2018 Debt Covenant Period, One [Member] Debt Covenant Period, One [Member] No later than December 31, 2019 Debt Covenant Period, Two [Member] Debt Covenant Period, Two [Member] Acquisition in excess of $100 million Debt Covenant Period, Three [Member] Debt Covenant Period, Three [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Principal amount Debt Instrument, Face Amount Debt issuance costs Debt Issuance Costs, Gross Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Draw on line of credit Long-term Line of Credit Cash distribution to DXC stockholders Payments of Dividends Preliminary fair value of cash purchase consideration received by Vencore Stockholders Preliminary fair value of cash consideration paid by USPS to extinguish certain existing Vencore indebtedness Payments To Acquire Business, Debt Extinguishment Payments To Acquire Business, Debt Extinguishment Repayments of lines of credit Repayments of Lines of Credit Debt covenant, ratio of indebtedness to EBITDA Debt Covenant, Ratio Of Indebtedness To Earnings Before Interest, Tax, Depreciation And Amortization Debt Covenant, Ratio Of Indebtedness To Earnings Before Interest, Tax, Depreciation And Amortization Debt covenant, consideration transferred threshold amount Debt Covenant, Business Combination Consideration Transferred Threshold Debt Covenant, Business Combination Consideration Transferred Threshold Debt covenant, ratio of EBITDA to interest expense Debt Covenant, Ratio Of Earnings Before Interest, Tax, Depreciation And Amortization To Interest Expense Debt Covenant, Ratio Of Earnings Before Interest, Tax, Depreciation And Amortization To Interest Expense Reduction in interest on debt Debt Instrument, Interest Rate, Increase (Decrease) Reduction in interest rate on unused commitment fee Line Of Credit Facility, Unused Capacity, Commitment Fee Percentage, Increase (Decrease) Line Of Credit Facility, Unused Capacity, Commitment Fee Percentage, Increase (Decrease) Income Statement [Abstract] Income tax expense (benefit) Basic EPS (in dollars per share) Diluted EPS (in dollars per share) Loss Contingencies [Table] Loss Contingencies [Table] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Surety Bond Surety Bond [Member] Loss Contingencies [Line Items] Outstanding letters of credit Letters of Credit Outstanding, Amount Outstanding surety bonds Guarantor Obligations, Current Carrying Value Schedule of Business Acquisitions, Consideration Exchanged Schedule of Business Acquisitions, by Acquisition [Table Text Block] Intangible Assets Acquired Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Summary of Pro Forma Information Business Acquisition, Pro Forma Information [Table Text Block] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Future Minimum Operating Lease Commitments Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block] KeyPoint KGS Holding Corp. [Member] KGS Holding Corp. [Member] Preliminary fair value of equity purchase consideration received by Vencore Stockholders Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Consideration transferred Business Combination, Consideration Transferred Number of shares issued in a business acquisition (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Closing price (in dollars per share) Share Price Acquired backlog Software Useful life Finite-Lived Intangible Asset, Useful Life Amortization period Finite-Lived Intangible Assets, Remaining Amortization Period Cash Cash and Other Investments [Member] Cash and Other Investments [Member] Equity funds Equity Securities [Member] Fixed income Other Alternative Securities [Member] Alternative Securities Asset allocation Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Schedule of Earnings per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Antidilutive Securities Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Current assets Accounts payable, accrued payroll, accrued expenses, and other current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Deferred revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Contract With Customer Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Contract With Customer Deferred tax liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent Other liabilities Net identifiable assets acquired Schedule of Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Long Term Debt Expected Maturities Schedule of Maturities of Long-term Debt [Table Text Block] Unbilled receivables Contract with Customer, Asset, Net Current portion of deferred revenue and advance contract payments Contract with Customer, Liability, Current Non-current portion of deferred revenue and advance contract payments Contract with Customer, Liability, Noncurrent Supplementary Data - Selected Quarterly Financial Data (Unaudited) Quarterly Financial Information [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Perspecta Enterprise Solutions LLC Perspecta Enterprise Solutions LLC [Member] Perspecta Enterprise Solutions LLC [Member] Financial Institution Financial Institution [Member] Financial Institution [Member] Line of Credit Line of Credit [Member] MARPA Facility MARPA Facility [Member] MARPA Facility [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Aggregate facility limit, first amendment Transfers of Financial Assets Accounted For As Sale, Securitization Facility Availability Transfers of Financial Assets Accounted For As Sale, Securitization Facility Availability MARPA facility term Transfers of Financial Assets Accounted For As Sale, Securitization Facility Term Transfers of Financial Assets Accounted For As Sale, Securitization Facility Term MARPA facility extension Transfers of Financial Assets Accounted For As Sale, Securitization Facility Renewal Term Transfers of Financial Assets Accounted For As Sale, Securitization Facility Renewal Term Sale of billed and unbilled receivables Transfer Of Financial Assets Accounted For As Sales, Billed And Unbilled Receivables Sold During Period Transfer Of Financial Assets Accounted For As Sales, Billed And Unbilled Receivables Sold During Period Collections corresponding to sale of receivables Proceeds from Collection of Finance Receivables Cash flow hedge adjustment, tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Earnings Per Share Earnings Per Share [Text Block] Revenue Revenue from Contract with Customer [Text Block] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Computers and related equipment Computer Equipment [Member] Furniture and other equipment Furniture and Fixtures [Member] Property and equipment—at cost Property, Plant and Equipment, Gross Less: accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Property, Plant and Equipment, Net Computers and related equipment under capital lease Capital Leased Assets, Gross Less: accumulated depreciation Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation Property and equipment under capital lease, net Capital Leases, Balance Sheet, Assets by Major Class, Net Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Treasury Stock Treasury Stock [Member] Parent Company Investment Parent Company Investment [Member] Parent Company Investment [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (in shares) Shares, Issued Beginning balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Impact of adoption of new accounting standard Cumulative Effect of New Accounting Principle in Period of Adoption Effects of purchase accounting Stockholders Equity, Acquisitions Stockholders Equity, Acquisitions Transfers to Parent, net Stockholders Equity Note, Transfer To Parent Stockholders Equity Note, Transfer To Parent Dividend to DXC prior to May 31, 2018 Adjustment To Additional Paid In Capital, Distribution Made Adjustment To Additional Paid In Capital, Distribution Made Spin-Off activity (in shares) Stock Issued During Period, Spinoff Transaction Stock Issued During Period, Spinoff Transaction Spin-Off activity Stockholders' Equity Note, Spinoff Transaction Mergers activity (in shares) Stock Issued During Period, Shares, Acquisitions Mergers activity Stock Issued During Period, Value, Acquisitions Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Share-based compensation expense Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Repurchase of common stock (in shares) Stock Repurchased During Period, Shares Repurchases of common stock Stock Repurchased During Period, Value Stock option exercises and other common stock transactions (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock option exercises and other common stock transactions Stock Issued During Period, Value, Stock Options Exercised Dividends declared ($0.20 per common share) Dividends, Common Stock, Cash Separation-related tax adjustment Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Ending balance (in shares) Ending balance Prospective Adoption of New Accounting Pronouncements [Table] Prospective Adoption of New Accounting Pronouncements [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Cumulative impact of ASC 606 Accounting Standards Update 2014-09 [Member] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Balances Without Adoption of ASC 606 Calculated under Revenue Guidance in Effect before Topic 606 [Member] Effect of Change Higher/(Lower) Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Item Effected [Line Items] Item Effected [Line Items] Assets: Assets [Abstract] Receivables, net Receivables, Net, Current Deferred contract costs Contract with Customer, Asset, Net, Current Other assets Other Assets, Noncurrent Liabilities and Stockholders’ Equity: Liabilities and Equity [Abstract] Deferred revenue and advance contract payments Deferred tax liabilities Deferred Income Tax Liabilities, Net Other long-term liabilities Other Liabilities, Noncurrent Total stockholders’ equity Stockholders' Equity Attributable to Parent Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Cash dividend per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared Number of acquired plans terminated Defined Contribution Plans Acquired, Terminated Defined Contribution Plans Acquired, Terminated Percent of match Defined Contribution Plan, Employer Matching Contribution, Percent of Match Percent of match of participant's annual salary Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Defense and Intelligence Civilian and Health Care Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Prime contractor Prime Contractor [Member] Prime Contractor [Member] Subcontractor Subcontractor [Member] Subcontractor [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenues Buildings Building [Member] Computers and related equipment Technology Equipment [Member] Property, plant and equipment useful life (in years) Property, Plant and Equipment, Useful Life Income Tax Contingency [Table] Income Tax Contingency [Table] Scenario, Forecast Scenario, Forecast [Member] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Income tax refunds receivable Income Taxes Receivable Refund received Proceeds from Income Tax Refunds Effective tax rate Effective Income Tax Rate Reconciliation, Percent Deferred tax assets Federal net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, Domestic Net operating loss carryforwards Operating Loss Carryforwards Unrecognized tax benefits Unrecognized tax benefits decrease Interest expense, net Unrecognized Tax Benefits Interest On Income Taxes Expense Net Of Tax This element represents interest expense recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity, net of tax. Employer contributions: Defined Benefit Plan, Expected Future Employer Contributions [Abstract] 2020 Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Benefit Payments: Defined Benefit Plan, Expected Future Benefit Payment [Abstract] 2020 Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 2024 Defined Benefit Plan, Expected Future Benefit Payment, Year Five 2025 - 2029 Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter Receivables Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Schedule of Disaggregation of Revenues Disaggregation of Revenue [Table Text Block] Schedule of Contract Assets and Contract Liabilities Contract with Customer, Asset and Liability [Table Text Block] Revenue Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Net income Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Subsequent Events Subsequent Events [Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Business Segment Information Segment Reporting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Leases with HPE's Wholly-Owned Leasing Subsidiary Lessee, Leases [Policy Text Block] Parent Company Investment Equity Method Investments [Policy Text Block] Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Stock-based Compensation Expense Compensation Related Costs, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Fair Value Fair Value of Financial Instruments, Policy [Policy Text Block] Concentrations of Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Acquisition Accounting and Goodwill Business Combinations Policy [Policy Text Block] Intangible Assets Intangible Assets, Finite-Lived, Policy [Policy Text Block] Long-Lived Asset Impairment Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy [Policy Text Block] Pension and Other Benefit Plans Pension and Other Postretirement Plans, Policy [Policy Text Block] Loss Contingencies Commitments and Contingencies, Policy [Policy Text Block] Recently Adopted Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Quarterly Financial Data Quarterly Financial Information [Table Text Block] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] U.S. federal government, including independent agencies Federal Customers [Member] Federal Customers [Member] Non-federal (state, local and other) Non-Federal Customers [Member] Non-Federal Customers [Member] Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at beginning of year (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number DXC awards replaced by Perspecta awards due to Spin-Off (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Issued in Period as a Result of Spin-Off Modification Share-based Compensation Arrangement by Share-based Payment Award, Options, Issued in Period as a Result of Spin-Off Modification Options converted to RSUs due to Spin-Off and Mergers (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Converted In Period As A Result Of Spin-Off Modification Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Converted In Period As A Result Of Spin-Off Modification Exercised (in shares) Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding, vested and exercisable at end of year (in shares) Weighted Average Exercise Price Per Share Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Outstanding at beginning of year (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price DXC awards replaced by Perspecta awards due to Spin-Off (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Issued from Spin-Off Modification, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Issued from Spin-Off Modification, Weighted Average Exercise Price Options converted to RSUs due to Spin-Off and Mergers (in dollars per share) Share-Based Compensation Arrangements By Share-Based Payment Award, Options, Converted From Spin-Off Modification, Weighted Average Exercise Price Share-Based Compensation Arrangements By Share-Based Payment Award, Options, Converted From Spin-Off Modification, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding, vested and exercisable at end of year (in dollars per share) Weighted Average Remaining Contractual Term in Years Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Contract term Capitalized Contract Cost, Amortization Period Summary of Amortizable Intangible Assets Estimated Future Amortization of Intangible Assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Billed trade receivables Billed Contracts Receivable Receivables, gross Accounts Receivable, Gross Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable Receivables, net Schedule of Provisions (Benefit) for Taxes Components Of Income Tax Provision [Table Text Block] Components Of Income Tax Provision [Table Text Block] Schedule of Difference Between the U.S. Statutory Tax Rate and the Effective Tax Rate Used Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Components of Deferred Tax Assets and Deferred Tax Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Summary of Unrecognized Tax Benefits Summary of Valuation Allowance [Table Text Block] Statement of Financial Position [Abstract] ASSETS Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Other receivables Other Receivables, Net, Current Prepaid expenses Prepaid Expense, Current Other current assets Other Assets, Current Total current assets Assets, Current Property and equipment, net Goodwill Intangible assets, net Other assets Total assets Assets LIABILITIES and STOCKHOLDERS’ EQUITY Current liabilities: Liabilities, Current [Abstract] Current maturities of long-term debt Long-term Debt, Current Maturities Current capital lease obligations Accounts payable Accounts Payable, Current Accrued payroll and related costs Employee-related Liabilities, Current Accrued expenses Accrued Liabilities, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Long-term debt, net of current maturities Long-term Debt, Excluding Current Maturities Non-current capital lease obligations Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Stockholders’ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Parent company investment, prior to Spin-Off Parent Company Investment Parent Company Investment Common stock, par value $0.01 per share; authorized 750,000,000; 165,844,994 issued and 163,099,080 outstanding at March 31, 2019 and 0 shares issued and outstanding at March 31, 2018 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock at cost, 2,745,914 and 0 shares at March 31, 2019 and 2018, respectively Treasury Stock, Value Total stockholders’ equity Total liabilities and stockholders' equity Liabilities and Equity Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract] Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract] Other assets Other long-term liabilities Liability, Other Postretirement Defined Benefit Plan, Noncurrent Operating Results by Reportable Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Reconciliation of Consolidated Operating Income to Income Before Taxes Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Stock-based Compensation Expense Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Schedule of Restricted Unit Activity Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block] Weighted-Average Fair Value and the Assumptions Used Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Summary of Stock Option Activity Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Income Taxes Income Tax Disclosure [Text Block] Related Party Transactions [Abstract] Cash pooling and general financing activities Related Party Transaction, Expenses from Transactions with Related Party Corporate allocations Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party Income taxes Related Party Transaction, Income Taxes From Transactions With Related Party Related Party Transaction, Income Taxes From Transactions With Related Party Transfers (to) from Parent, net Related Party Transaction, Due from (to) Related Party Depreciation expense for owned property and equipment Owned Property and Equipment [Member] Owned Property and Equipment [Member] Depreciation expense for property and equipment under capital lease Assets Held under Capital Leases [Member] Total depreciation expense Depreciation Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Expected return on assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Recognition of net actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Net periodic pension expense (income) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Effective Income Tax Rate Reconciliation, Percent [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] U.S. federal statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State income taxes, net of federal impact Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Non-deductible transaction costs Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent Remeasurement of state deferred income tax items Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent State valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Research and development credit Effective Income Tax Rate Reconciliation, Tax Credit, Research, Percent Unrecognized tax benefits Effective Income Tax Rate Change In Uncertain Tax Positions The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by the change in uncertain tax positions recorded during the period. Interest on federal tax refund, net of tax expense Effective Income Tax Rate Reconciliation, Interest On Federal Tax Refund, Percent Effective Income Tax Rate Reconciliation, Interest On Federal Tax Refund, Percent Impact of Tax Act Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act Of 2017, Percent Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act Of 2017, Percent Other items, net Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective tax rate Stockholders' equity: Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Common stock in treasury, at cost (in shares) Treasury Stock, Shares Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair value Estimate of Fair Value Measurement [Member] Carrying value Reported Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Long-term debt fair value disclosure Debt Instrument, Fair Value Disclosure Related Party Transactions and Parent Company Investment Related Party Transactions Disclosure [Text Block] Weighted average fair value Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Expected Dividend Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected term in years Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Current Liabilities Other Current Liabilities [Member] Other Liabilities Other Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative liability, fair value Derivative Liability, Fair Value, Gross Liability Transfers (to) from Parent, net Schedule of Related Party Transactions [Table Text Block] Acquisitions Business Combination Disclosure [Text Block] Property and Equipment Property, Plant and Equipment Disclosure [Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] ASU 2016-02 Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Right-of-use asset Operating Lease, Right-of-Use Asset Lease liability Operating Lease, Liability Total fair value of consideration transferred for USPS Valuation adjustments, estimated fair value, increase in net assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Net Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Net Assets Valuation adjustments, estimated fair value, increase in total assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Assets Valuation adjustments, estimated fair value, increase in intangible assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Valuation adjustments, estimated fair value, increase in current assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets Valuation adjustments, estimated fair value, decrease in property and equipment Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment Valuation adjustments, estimated fair value, increase in current capital lease liability Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Liabilities Common share information: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Dilutive effect of stock options and equity awards (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average common shares outstanding for diluted EPS (in shares) Earnings per common share: Earnings Per Share, Basic [Abstract] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] Cost-reimbursable Cost-reimbursable Contract [Member] Cost-reimbursable Contract [Member] Fixed-price Fixed-price Contract [Member] Time-and-materials Time-and-materials Contract [Member] Changes in the Carrying Amount of Goodwill by Segment Schedule of Goodwill [Table Text Block] Segment profit Not allocated to segments: Income Statement Compensation Expense Items [Abstract] Stock-based compensation Allocated Share-based Compensation Expense Amortization of acquired intangible assets Restructuring costs Separation and integration-related costs Interest expense, net Other unallocated, net Other Nonoperating Income (Expense) Extinguishment of Vencore HC and KGS HC debt and related costs Acquiree-related transaction costs Business Acquisition, Transaction Costs Tax deductible goodwill Business Acquisition, Goodwill, Expected Tax Deductible Amount Decrease in goodwill due to fair value adjustments Goodwill, Purchase Accounting Adjustments Goodwill acquired during period Goodwill Goodwill Disclosure [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Revenue from related parties Revenue from Related Parties Related party expenses Costs and Expenses, Related Party Stock-based compensation expense Income tax benefit Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Stock-based compensation expense, net of tax Share Based Compensation Net Of Tax The aggregate amount of noncash, net of tax, equity-based employee remuneration. This may include the value of stock options, amortization of restricted stock, and adjustment for officers compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. Statement of Cash Flows [Abstract]