3.19.1 html 333 494 1 true 112 0 false 10 false false R1.htm 0001000 - Document - Document And Entity Information Sheet http://perspecta.com/role/DocumentAndEntityInformation Document And Entity Information Cover 1 false false R2.htm 1001000 - Statement - CONSOLIDATED COMBINED STATEMENTS OF OPERATIONS Sheet http://perspecta.com/role/ConsolidatedCombinedStatementsOfOperations CONSOLIDATED COMBINED STATEMENTS OF OPERATIONS Statements 2 false false R3.htm 1002000 - Statement - CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME Sheet http://perspecta.com/role/ConsolidatedCombinedStatementsOfComprehensiveIncome CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME Statements 3 false false R4.htm 1002501 - Statement - CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) Sheet http://perspecta.com/role/ConsolidatedCombinedStatementsOfComprehensiveIncomeParenthetical CONSOLIDATED COMBINED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) Statements 4 false false R5.htm 1003000 - Statement - CONSOLIDATED COMBINED BALANCE SHEETS Sheet http://perspecta.com/role/ConsolidatedCombinedBalanceSheets CONSOLIDATED COMBINED BALANCE SHEETS Statements 5 false false R6.htm 1003501 - Statement - CONSOLIDATED COMBINED BALANCE SHEETS (Parenthetical) Sheet http://perspecta.com/role/ConsolidatedCombinedBalanceSheetsParenthetical CONSOLIDATED COMBINED BALANCE SHEETS (Parenthetical) Statements 6 false false R7.htm 1004000 - Statement - CONSOLIDATED COMBINED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Sheet http://perspecta.com/role/ConsolidatedCombinedStatementsOfChangesInStockholdersEquity CONSOLIDATED COMBINED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Statements 7 false false R8.htm 1004001 - Statement - CONSOLIDATED COMBINED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) Sheet http://perspecta.com/role/ConsolidatedCombinedStatementsOfChangesInStockholdersEquityParenthetical CONSOLIDATED COMBINED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) Statements 8 false false R9.htm 1005000 - Statement - CONSOLIDATED COMBINED STATEMENTS OF CASH FLOWS Sheet http://perspecta.com/role/ConsolidatedCombinedStatementsOfCashFlows CONSOLIDATED COMBINED STATEMENTS OF CASH FLOWS Statements 9 false false R10.htm 2101100 - Disclosure - Overview and Summary of Significant Accounting Policies Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPolicies Overview and Summary of Significant Accounting Policies Notes 10 false false R11.htm 2102100 - Disclosure - Acquisitions Sheet http://perspecta.com/role/Acquisitions Acquisitions Notes 11 false false R12.htm 2103100 - Disclosure - Revenue Sheet http://perspecta.com/role/Revenue Revenue Notes 12 false false R13.htm 2104100 - Disclosure - Earnings Per Share Sheet http://perspecta.com/role/EarningsPerShare Earnings Per Share Notes 13 false false R14.htm 2104100 - Disclosure - Receivables Sheet http://perspecta.com/role/Receivables Receivables Notes 14 false false R15.htm 2106100 - Disclosure - Restructuring Sheet http://perspecta.com/role/Restructuring Restructuring Notes 15 false false R16.htm 2107100 - Disclosure - Fair Value Sheet http://perspecta.com/role/FairValue Fair Value Notes 16 false false R17.htm 2108100 - Disclosure - Derivative Instruments Sheet http://perspecta.com/role/DerivativeInstruments Derivative Instruments Notes 17 false false R18.htm 2109100 - Disclosure - Goodwill Sheet http://perspecta.com/role/Goodwill Goodwill Notes 18 false false R19.htm 2109100 - Disclosure - Property and Equipment Sheet http://perspecta.com/role/PropertyAndEquipment Property and Equipment Notes 19 false false R20.htm 2111100 - Disclosure - Intangible Assets Sheet http://perspecta.com/role/IntangibleAssets Intangible Assets Notes 20 false false R21.htm 2112100 - Disclosure - Debt Sheet http://perspecta.com/role/Debt Debt Notes 21 false false R22.htm 2113100 - Disclosure - Capital Leases Sheet http://perspecta.com/role/CapitalLeases Capital Leases Notes 22 false false R23.htm 2114100 - Disclosure - Pension and Other Benefit Plans Sheet http://perspecta.com/role/PensionAndOtherBenefitPlans Pension and Other Benefit Plans Notes 23 false false R24.htm 2115100 - Disclosure - Income Taxes Sheet http://perspecta.com/role/IncomeTaxes Income Taxes Notes 24 false false R25.htm 2116100 - Disclosure - Related Party Transactions and Parent Company Investment Sheet http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestment Related Party Transactions and Parent Company Investment Notes 25 false false R26.htm 2117100 - Disclosure - Stock-based Compensation Sheet http://perspecta.com/role/StockBasedCompensation Stock-based Compensation Notes 26 false false R27.htm 2117100 - Disclosure - Stockholders' Equity Sheet http://perspecta.com/role/StockholdersEquity Stockholders' Equity Notes 27 false false R28.htm 2119100 - Disclosure - Segment Information Sheet http://perspecta.com/role/SegmentInformation Segment Information Notes 28 false false R29.htm 2121100 - Disclosure - Commitments and Contingencies Sheet http://perspecta.com/role/CommitmentsAndContingencies Commitments and Contingencies Notes 29 false false R30.htm 2123100 - Disclosure - Subsequent Events Sheet http://perspecta.com/role/SubsequentEvents Subsequent Events Notes 30 false false R31.htm 2132100 - Disclosure - Supplementary Data - Selected Quarterly Financial Data (Unaudited) Sheet http://perspecta.com/role/SupplementaryDataSelectedQuarterlyFinancialDataUnaudited Supplementary Data - Selected Quarterly Financial Data (Unaudited) Notes 31 false false R32.htm 2201201 - Disclosure - Overview and Summary of Significant Accounting Policies (Policies) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesPolicies Overview and Summary of Significant Accounting Policies (Policies) Policies http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPolicies 32 false false R33.htm 2301302 - Disclosure - Overview and Summary of Significant Accounting Policies (Tables) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesTables Overview and Summary of Significant Accounting Policies (Tables) Tables http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPolicies 33 false false R34.htm 2302301 - Disclosure - Acquisitions (Tables) Sheet http://perspecta.com/role/AcquisitionsTables Acquisitions (Tables) Tables http://perspecta.com/role/Acquisitions 34 false false R35.htm 2303301 - Disclosure - Revenue (Tables) Sheet http://perspecta.com/role/RevenueTables Revenue (Tables) Tables http://perspecta.com/role/Revenue 35 false false R36.htm 2304301 - Disclosure - Earnings Per Share (Tables) Sheet http://perspecta.com/role/EarningsPerShareTables Earnings Per Share (Tables) Tables http://perspecta.com/role/EarningsPerShare 36 false false R37.htm 2304301 - Disclosure - Receivables (Tables) Sheet http://perspecta.com/role/ReceivablesTables Receivables (Tables) Tables http://perspecta.com/role/Receivables 37 false false R38.htm 2306301 - Disclosure - Restructuring (Tables) Sheet http://perspecta.com/role/RestructuringTables Restructuring (Tables) Tables http://perspecta.com/role/Restructuring 38 false false R39.htm 2309301 - Disclosure - Goodwill (Tables) Sheet http://perspecta.com/role/GoodwillTables Goodwill (Tables) Tables http://perspecta.com/role/Goodwill 39 false false R40.htm 2309301 - Disclosure - Property and Equipment (Tables) Sheet http://perspecta.com/role/PropertyAndEquipmentTables Property and Equipment (Tables) Tables http://perspecta.com/role/PropertyAndEquipment 40 false false R41.htm 2311301 - Disclosure - Intangible Assets (Tables) Sheet http://perspecta.com/role/IntangibleAssetsTables Intangible Assets (Tables) Tables http://perspecta.com/role/IntangibleAssets 41 false false R42.htm 2312301 - Disclosure - Debt (Tables) Sheet http://perspecta.com/role/DebtTables Debt (Tables) Tables http://perspecta.com/role/Debt 42 false false R43.htm 2313301 - Disclosure - Capital Leases (Tables) Sheet http://perspecta.com/role/CapitalLeasesTables Capital Leases (Tables) Tables http://perspecta.com/role/CapitalLeases 43 false false R44.htm 2314301 - Disclosure - Pensions and Other Benefit Plans (Tables) Sheet http://perspecta.com/role/PensionsAndOtherBenefitPlansTables Pensions and Other Benefit Plans (Tables) Tables 44 false false R45.htm 2315301 - Disclosure - Income Taxes (Tables) Sheet http://perspecta.com/role/IncomeTaxesTables Income Taxes (Tables) Tables http://perspecta.com/role/IncomeTaxes 45 false false R46.htm 2316301 - Disclosure - Related Party Transactions and Parent Company Investment (Tables) Sheet http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestmentTables Related Party Transactions and Parent Company Investment (Tables) Tables http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestment 46 false false R47.htm 2317301 - Disclosure - Stock-based Compensation (Tables) Sheet http://perspecta.com/role/StockBasedCompensationTables Stock-based Compensation (Tables) Tables http://perspecta.com/role/StockBasedCompensation 47 false false R48.htm 2319301 - Disclosure - Segment Information (Tables) Sheet http://perspecta.com/role/SegmentInformationTables Segment Information (Tables) Tables http://perspecta.com/role/SegmentInformation 48 false false R49.htm 2321301 - Disclosure - Commitments and Contingencies (Tables) Sheet http://perspecta.com/role/CommitmentsAndContingenciesTables Commitments and Contingencies (Tables) Tables http://perspecta.com/role/CommitmentsAndContingencies 49 false false R50.htm 2332301 - Disclosure - Supplementary Data - Selected Quarterly Financial Data (Unaudited) (Tables) Sheet http://perspecta.com/role/SupplementaryDataSelectedQuarterlyFinancialDataUnauditedTables Supplementary Data - Selected Quarterly Financial Data (Unaudited) (Tables) Tables http://perspecta.com/role/SupplementaryDataSelectedQuarterlyFinancialDataUnaudited 50 false false R51.htm 2401403 - Disclosure - Overview and Summary of Significant Accounting Policies - Narrative (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesNarrativeDetails Overview and Summary of Significant Accounting Policies - Narrative (Details) Details http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesTables 51 false false R52.htm 2401404 - Disclosure - Overview and Summary of Significant Accounting Policies - Revenue and Income Before Taxes (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesRevenueAndIncomeBeforeTaxesDetails Overview and Summary of Significant Accounting Policies - Revenue and Income Before Taxes (Details) Details 52 false false R53.htm 2401405 - Disclosure - Overview and Summary of Significant Accounting Policies - Revenue Recognition Narrative (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesRevenueRecognitionNarrativeDetails Overview and Summary of Significant Accounting Policies - Revenue Recognition Narrative (Details) Details 53 false false R54.htm 2401406 - Disclosure - Overview and Summary of Significant Accounting Policies - Property and Equipment (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails Overview and Summary of Significant Accounting Policies - Property and Equipment (Details) Details 54 false false R55.htm 2401407 - Disclosure - Overview and Summary of Significant Accounting Policies - Intangible Assets (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesIntangibleAssetsDetails Overview and Summary of Significant Accounting Policies - Intangible Assets (Details) Details 55 false false R56.htm 2401408 - Disclosure - Overview and Summary of Significant Accounting Policies - Cumulative Impact of Adoption ASC 606 (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesCumulativeImpactOfAdoptionAsc606Details Overview and Summary of Significant Accounting Policies - Cumulative Impact of Adoption ASC 606 (Details) Details 56 false false R57.htm 2401409 - Disclosure - Overview and Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) Sheet http://perspecta.com/role/OverviewAndSummaryOfSignificantAccountingPoliciesRecentlyIssuedAccountingPronouncementsDetails Overview and Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) Details 57 false false R58.htm 2402402 - Disclosure - Acquisitions - Narrative (Details) Sheet http://perspecta.com/role/AcquisitionsNarrativeDetails Acquisitions - Narrative (Details) Details 58 false false R59.htm 2402403 - Disclosure - Acquisitions - Schedule of Consideration Exchanged (Details) Sheet http://perspecta.com/role/AcquisitionsScheduleOfConsiderationExchangedDetails Acquisitions - Schedule of Consideration Exchanged (Details) Details 59 false false R60.htm 2402404 - Disclosure - Acquisitions - Schedule of Assets Acquired and Liabilities Assumed (Details) Sheet http://perspecta.com/role/AcquisitionsScheduleOfAssetsAcquiredAndLiabilitiesAssumedDetails Acquisitions - Schedule of Assets Acquired and Liabilities Assumed (Details) Details 60 false false R61.htm 2402405 - Disclosure - Acquisitions - Intangible Assets Acquired (Details) Sheet http://perspecta.com/role/AcquisitionsIntangibleAssetsAcquiredDetails Acquisitions - Intangible Assets Acquired (Details) Details 61 false false R62.htm 2402406 - Disclosure - Acquisitions - Pro Forma Information (Details) Sheet http://perspecta.com/role/AcquisitionsProFormaInformationDetails Acquisitions - Pro Forma Information (Details) Details 62 false false R63.htm 2402407 - Disclosure - Acquisitions - HPES Narrative (Details) Sheet http://perspecta.com/role/AcquisitionsHpesNarrativeDetails Acquisitions - HPES Narrative (Details) Details 63 false false R64.htm 2402408 - Disclosure - Acquisitions - Summary of HPES Purchase Price (Details) Sheet http://perspecta.com/role/AcquisitionsSummaryOfHpesPurchasePriceDetails Acquisitions - Summary of HPES Purchase Price (Details) Details 64 false false R65.htm 2402411 - Disclosure - Acquisitions - Summary of HPES Pro Forma Information (Details) Sheet http://perspecta.com/role/AcquisitionsSummaryOfHpesProFormaInformationDetails Acquisitions - Summary of HPES Pro Forma Information (Details) Details 65 false false R66.htm 2403402 - Disclosure - Revenue - Schedule of Revenues Disaggregated By Contract Type (Details) Sheet http://perspecta.com/role/RevenueScheduleOfRevenuesDisaggregatedByContractTypeDetails Revenue - Schedule of Revenues Disaggregated By Contract Type (Details) Details 66 false false R67.htm 2403403 - Disclosure - Revenue - Schedule of Revenues Disaggregated By Prime or Subcontractor (Details) Sheet http://perspecta.com/role/RevenueScheduleOfRevenuesDisaggregatedByPrimeOrSubcontractorDetails Revenue - Schedule of Revenues Disaggregated By Prime or Subcontractor (Details) Details 67 false false R68.htm 2403404 - Disclosure - Revenue - Schedule of Revenues Disaggregated By Customer Type (Details) Sheet http://perspecta.com/role/RevenueScheduleOfRevenuesDisaggregatedByCustomerTypeDetails Revenue - Schedule of Revenues Disaggregated By Customer Type (Details) Details 68 false false R69.htm 2403405 - Disclosure - Revenue - Performance Obligations Narrative (Details) Sheet http://perspecta.com/role/RevenuePerformanceObligationsNarrativeDetails Revenue - Performance Obligations Narrative (Details) Details 69 false false R70.htm 2403406 - Disclosure - Revenue - Schedule of Contract Assets and Contract Liabilities (Details) Sheet http://perspecta.com/role/RevenueScheduleOfContractAssetsAndContractLiabilitiesDetails Revenue - Schedule of Contract Assets and Contract Liabilities (Details) Details 70 false false R71.htm 2403407 - Disclosure - Revenue - Narrative (Details) Sheet http://perspecta.com/role/RevenueNarrativeDetails Revenue - Narrative (Details) Details 71 false false R72.htm 2404402 - Disclosure - Earnings Per Share - Schedule of Earnings per Share (Details) Sheet http://perspecta.com/role/EarningsPerShareScheduleOfEarningsPerShareDetails Earnings Per Share - Schedule of Earnings per Share (Details) Details 72 false false R73.htm 2404402 - Disclosure - Receivables - Schedule of Receivables (Details) Sheet http://perspecta.com/role/ReceivablesScheduleOfReceivablesDetails Receivables - Schedule of Receivables (Details) Details 73 false false R74.htm 2404403 - Disclosure - Earnings Per Share - Schedule of Antidilutive Shares (Details) Sheet http://perspecta.com/role/EarningsPerShareScheduleOfAntidilutiveSharesDetails Earnings Per Share - Schedule of Antidilutive Shares (Details) Details 74 false false R75.htm 2404403 - Disclosure - Receivables - Sale of Receivables (Details) Sheet http://perspecta.com/role/ReceivablesSaleOfReceivablesDetails Receivables - Sale of Receivables (Details) Details 75 false false R76.htm 2406402 - Disclosure - Restructuring (Details) Sheet http://perspecta.com/role/RestructuringDetails Restructuring (Details) Details http://perspecta.com/role/RestructuringTables 76 false false R77.htm 2406403 - Disclosure - Restructuring - Restructuring Liability (Details) Sheet http://perspecta.com/role/RestructuringRestructuringLiabilityDetails Restructuring - Restructuring Liability (Details) Details 77 false false R78.htm 2407401 - Disclosure - Fair Value - Narrative (Details) Sheet http://perspecta.com/role/FairValueNarrativeDetails Fair Value - Narrative (Details) Details 78 false false R79.htm 2408401 - Disclosure - Derivative Instruments - Narrative (Details) Sheet http://perspecta.com/role/DerivativeInstrumentsNarrativeDetails Derivative Instruments - Narrative (Details) Details 79 false false R80.htm 2408402 - Disclosure - Derivative Instruments - Fair Value of Derivative Instruments (Details) Sheet http://perspecta.com/role/DerivativeInstrumentsFairValueOfDerivativeInstrumentsDetails Derivative Instruments - Fair Value of Derivative Instruments (Details) Details 80 false false R81.htm 2409402 - Disclosure - Goodwill (Details) Sheet http://perspecta.com/role/GoodwillDetails Goodwill (Details) Details http://perspecta.com/role/GoodwillTables 81 false false R82.htm 2409402 - Disclosure - Property and Equipment (Details) Sheet http://perspecta.com/role/PropertyAndEquipmentDetails Property and Equipment (Details) Details http://perspecta.com/role/PropertyAndEquipmentTables 82 false false R83.htm 2409403 - Disclosure - Property and Equipment - Depreciation Expense (Details) Sheet http://perspecta.com/role/PropertyAndEquipmentDepreciationExpenseDetails Property and Equipment - Depreciation Expense (Details) Details 83 false false R84.htm 2409404 - Disclosure - Property and Equipment - Narrative (Details) Sheet http://perspecta.com/role/PropertyAndEquipmentNarrativeDetails Property and Equipment - Narrative (Details) Details 84 false false R85.htm 2411402 - Disclosure - Intangible Assets - Summary of Intangible Assets (Details) Sheet http://perspecta.com/role/IntangibleAssetsSummaryOfIntangibleAssetsDetails Intangible Assets - Summary of Intangible Assets (Details) Details 85 false false R86.htm 2411403 - Disclosure - Intangible Assets - Narrative (Details) Sheet http://perspecta.com/role/IntangibleAssetsNarrativeDetails Intangible Assets - Narrative (Details) Details 86 false false R87.htm 2411404 - Disclosure - Intangible Assets - Schedule of Future Amortization Expenses (Details) Sheet http://perspecta.com/role/IntangibleAssetsScheduleOfFutureAmortizationExpensesDetails Intangible Assets - Schedule of Future Amortization Expenses (Details) Details 87 false false R88.htm 2412402 - Disclosure - Debt - Schedule of Debt (Details) Sheet http://perspecta.com/role/DebtScheduleOfDebtDetails Debt - Schedule of Debt (Details) Details 88 false false R89.htm 2412403 - Disclosure - Debt - Narrative (Details) Sheet http://perspecta.com/role/DebtNarrativeDetails Debt - Narrative (Details) Details 89 false false R90.htm 2412404 - Disclosure - Debt - Maturities of Long-Term Debt (Details) Sheet http://perspecta.com/role/DebtMaturitiesOfLongTermDebtDetails Debt - Maturities of Long-Term Debt (Details) Details 90 false false R91.htm 2413402 - Disclosure - Capital Leases - Narrative (Details) Sheet http://perspecta.com/role/CapitalLeasesNarrativeDetails Capital Leases - Narrative (Details) Details 91 false false R92.htm 2413403 - Disclosure - Capital Leases - Schedule of Future Minimum Lease Payments (Details) Sheet http://perspecta.com/role/CapitalLeasesScheduleOfFutureMinimumLeasePaymentsDetails Capital Leases - Schedule of Future Minimum Lease Payments (Details) Details 92 false false R93.htm 2414402 - Disclosure - Pension and Other Benefit Plans - Narrative (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansNarrativeDetails Pension and Other Benefit Plans - Narrative (Details) Details 93 false false R94.htm 2414403 - Disclosure - Pension and Other Benefit Plans - Reconciliation of Projected Benefit Obligation (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansReconciliationOfProjectedBenefitObligationDetails Pension and Other Benefit Plans - Reconciliation of Projected Benefit Obligation (Details) Details 94 false false R95.htm 2414404 - Disclosure - Pension and Other Benefit Plans - Amounts Recognized in Balance Sheet for Pension Plan Liabilities (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansAmountsRecognizedInBalanceSheetForPensionPlanLiabilitiesDetails Pension and Other Benefit Plans - Amounts Recognized in Balance Sheet for Pension Plan Liabilities (Details) Details 95 false false R96.htm 2414405 - Disclosure - Pension and Other Benefit Plans - Schedule of Components of Net Periodic Pension Expense (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansScheduleOfComponentsOfNetPeriodicPensionExpenseDetails Pension and Other Benefit Plans - Schedule of Components of Net Periodic Pension Expense (Details) Details 96 false false R97.htm 2414406 - Disclosure - Pension and Other Benefit Plans - Schedule of Weighted-Average Rates Used to Determine Net Periodic Pension Cost (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansScheduleOfWeightedAverageRatesUsedToDetermineNetPeriodicPensionCostDetails Pension and Other Benefit Plans - Schedule of Weighted-Average Rates Used to Determine Net Periodic Pension Cost (Details) Details 97 false false R98.htm 2414407 - Disclosure - Pension and Other Benefit Plans - Asset Allocations (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansAssetAllocationsDetails Pension and Other Benefit Plans - Asset Allocations (Details) Details 98 false false R99.htm 2414408 - Disclosure - Pension and Other Benefit Plans - Fair Value by Investment Category and Level Within Fair Value Hierarchy (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansFairValueByInvestmentCategoryAndLevelWithinFairValueHierarchyDetails Pension and Other Benefit Plans - Fair Value by Investment Category and Level Within Fair Value Hierarchy (Details) Details 99 false false R100.htm 2414409 - Disclosure - Pension and Other Benefit Plans - Reconciliation of Assets Valued Using Significant Unobservable Inputs (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansReconciliationOfAssetsValuedUsingSignificantUnobservableInputsDetails Pension and Other Benefit Plans - Reconciliation of Assets Valued Using Significant Unobservable Inputs (Details) Details 100 false false R101.htm 2414410 - Disclosure - Pension and Other Benefit Plans - Expected Future Contributions and Benefit Payments (Details) Sheet http://perspecta.com/role/PensionAndOtherBenefitPlansExpectedFutureContributionsAndBenefitPaymentsDetails Pension and Other Benefit Plans - Expected Future Contributions and Benefit Payments (Details) Details 101 false false R102.htm 2415402 - Disclosure - Income Taxes - Narrative (Details) Sheet http://perspecta.com/role/IncomeTaxesNarrativeDetails Income Taxes - Narrative (Details) Details 102 false false R103.htm 2415403 - Disclosure - Income Taxes - Provision (Benefit) For Taxes (Details) Sheet http://perspecta.com/role/IncomeTaxesProvisionBenefitForTaxesDetails Income Taxes - Provision (Benefit) For Taxes (Details) Details 103 false false R104.htm 2415404 - Disclosure - Income Taxes - Effective Tax Rate Reconciliation (Details) Sheet http://perspecta.com/role/IncomeTaxesEffectiveTaxRateReconciliationDetails Income Taxes - Effective Tax Rate Reconciliation (Details) Details 104 false false R105.htm 2415405 - Disclosure - Income Taxes - Deferred Tax Assets (Liabilities) (Details) Sheet http://perspecta.com/role/IncomeTaxesDeferredTaxAssetsLiabilitiesDetails Income Taxes - Deferred Tax Assets (Liabilities) (Details) Details 105 false false R106.htm 2415406 - Disclosure - Income Taxes - Unrecognized Tax Benefits (Details) Sheet http://perspecta.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails Income Taxes - Unrecognized Tax Benefits (Details) Details 106 false false R107.htm 2416402 - Disclosure - Related Party Transactions and Parent Company Investment (Details) Sheet http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestmentDetails Related Party Transactions and Parent Company Investment (Details) Details http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestmentTables 107 false false R108.htm 2416403 - Disclosure - Related Party Transactions and Parent Company Investment - Transfer (To) From Parent (Details) Sheet http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestmentTransferToFromParentDetails Related Party Transactions and Parent Company Investment - Transfer (To) From Parent (Details) Details http://perspecta.com/role/RelatedPartyTransactionsAndParentCompanyInvestmentTables 108 false false R109.htm 2417401 - Disclosure - Stockholders' Equity - Capital Stock, Cash Dividend and Share Repurchases (Details) Sheet http://perspecta.com/role/StockholdersEquityCapitalStockCashDividendAndShareRepurchasesDetails Stockholders' Equity - Capital Stock, Cash Dividend and Share Repurchases (Details) Details 109 false false R110.htm 2417402 - Disclosure - Stock-based Compensation - Narrative (Details) Sheet http://perspecta.com/role/StockBasedCompensationNarrativeDetails Stock-based Compensation - Narrative (Details) Details 110 false false R111.htm 2417403 - Disclosure - Stock-based Compensation - Schedule of Stock-Based Compensation (Details) Sheet http://perspecta.com/role/StockBasedCompensationScheduleOfStockBasedCompensationDetails Stock-based Compensation - Schedule of Stock-Based Compensation (Details) Details 111 false false R112.htm 2417404 - Disclosure - Stock-based Compensation - Schedule of RSUs and PSUs (Details) Sheet http://perspecta.com/role/StockBasedCompensationScheduleOfRsusAndPsusDetails Stock-based Compensation - Schedule of RSUs and PSUs (Details) Details 112 false false R113.htm 2417405 - Disclosure - Stock-based Compensation - Schedule of Assumptions Used to Calculate Share-Based Compensation Expense (Details) Sheet http://perspecta.com/role/StockBasedCompensationScheduleOfAssumptionsUsedToCalculateShareBasedCompensationExpenseDetails Stock-based Compensation - Schedule of Assumptions Used to Calculate Share-Based Compensation Expense (Details) Details 113 false false R114.htm 2417406 - Disclosure - Stock-based Compensation - Summary of Stock Option Activity (Details) Sheet http://perspecta.com/role/StockBasedCompensationSummaryOfStockOptionActivityDetails Stock-based Compensation - Summary of Stock Option Activity (Details) Details 114 false false R115.htm 2419402 - Disclosure - Segment Information (Details) Sheet http://perspecta.com/role/SegmentInformationDetails Segment Information (Details) Details http://perspecta.com/role/SegmentInformationTables 115 false false R116.htm 2419403 - Disclosure - Segment Information - Reconciliation of Reportable Segment Profit to the Statements of Operations (Details) Sheet http://perspecta.com/role/SegmentInformationReconciliationOfReportableSegmentProfitToStatementsOfOperationsDetails Segment Information - Reconciliation of Reportable Segment Profit to the Statements of Operations (Details) Details 116 false false R117.htm 2421402 - Disclosure - Commitments and Contingencies - Contingencies (Details) Sheet http://perspecta.com/role/CommitmentsAndContingenciesContingenciesDetails Commitments and Contingencies - Contingencies (Details) Details 117 false false R118.htm 2421403 - Disclosure - Commitments and Contingencies - Guarantees (Details) Sheet http://perspecta.com/role/CommitmentsAndContingenciesGuaranteesDetails Commitments and Contingencies - Guarantees (Details) Details 118 false false R119.htm 2421404 - Disclosure - Commitments and Contingencies - Lease Commitments (Details) Sheet http://perspecta.com/role/CommitmentsAndContingenciesLeaseCommitmentsDetails Commitments and Contingencies - Lease Commitments (Details) Details 119 false false R120.htm 2423401 - Disclosure - Subsequent Events (Details) Sheet http://perspecta.com/role/SubsequentEventsDetails Subsequent Events (Details) Details http://perspecta.com/role/SubsequentEvents 120 false false R121.htm 2432402 - Disclosure - Supplementary Data - Selected Quarterly Financial Data (Unaudited) (Details) Sheet http://perspecta.com/role/SupplementaryDataSelectedQuarterlyFinancialDataUnauditedDetails Supplementary Data - Selected Quarterly Financial Data (Unaudited) (Details) Details http://perspecta.com/role/SupplementaryDataSelectedQuarterlyFinancialDataUnauditedTables 121 false false All Reports Book All Reports prsp-20190331.xml prsp-20190331.xsd prsp-20190331_cal.xml prsp-20190331_def.xml prsp-20190331_lab.xml prsp-20190331_pre.xml http://fasb.org/us-gaap/2018-01-31 http://fasb.org/srt/2018-01-31 http://xbrl.sec.gov/dei/2018-01-31 true true