Basis of Presentation (Policies)	3 Months Ended
Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) and should be read in conjunction with the information contained in the Company's Annual Report on Form 10-K for the year ended March 31, 2023. The interim period unaudited condensed consolidated financial statements are presented as described below. Certain information and disclosures normally required for annual financial statements have been condensed or omitted pursuant to GAAP and SEC rules and regulations. In the opinion of management, all adjustments considered necessary for fair presentation of the results of the interim periods presented have been included. The Company’s fiscal year ends on March 31 and, unless otherwise noted, references to fiscal year or fiscal are for fiscal years ended March 31. The results of operations for the three months ended June 30, 2023 are not necessarily indicative of results to be expected for the full fiscal year. The condensed consolidated financial statements and notes of the Company include its subsidiaries, and other entities over which the Company has a controlling financial interest or where the Company is a primary beneficiary. The Company uses the equity method to account for investments in entities that it does not control if it is otherwise able to exert significant influence over the entities' operating and financial policies. Equity investments in entities over which the Company does not have the ability to exercise significant influence and whose securities do not have a readily determinable fair value are carried at cost or cost net of other-than-temporary impairments. Certain amounts reported in the Company's prior fiscal year condensed consolidated financial statements have been reclassified to conform to the current fiscal year presentation.
Accounting Estimates	Accounting Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting periods. Areas of the financial statements where estimates may have the most significant effect include the provision for claimed indirect costs, valuation and expected lives of tangible and intangible assets, impairment of long-lived assets, accrued liabilities, revenue recognition, including the accrual of indirect costs, bonus and other incentive compensation, stock-based compensation, reserves for uncertain tax positions and valuation allowances on deferred tax assets, provisions for income taxes, postretirement obligations, collectability of receivables, and loss accruals for litigation. Actual results experienced by the Company may differ materially from management's estimates.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“Topic 848”). The guidance is intended to provide relief for entities impacted by reference rate reform. Topic 848 contains provisions and optional accounting expedients designed to simplify requirements around the designation of hedging relationships, probability assessments of hedged forecasted transactions, and accounting for modifications of contracts that refer to the London Interbank Offered Rate (“LIBOR”) or other rates affected by reference rate reform. The guidance is elective and is effective on the date of issuance. Topic 848 is applied prospectively to contract modifications and as of the effective date for existing and new eligible hedging relationships. During the first quarter of fiscal 2024, the Company modified its interest rate swap agreements to transition from LIBOR-indexed to term SOFR-indexed periodic swap payments to align with interest payments in connection with its term SOFR-indexed debt. As such, the Company elected the optional expedients under Topic 848 which allows the cash flow hedge to continue being recognized under hedge accounting without de-designation upon a change in critical terms affected by the reference rate reform. The adoption of this guidance did not have a material impact on the condensed consolidated financial statements and disclosures. Recent Accounting Pronouncements Not Yet Adopted Accounting and reporting pronouncements effective after June 30, 2023 and issued through the filing date are not expected to have a material impact on the Company's condensed consolidated financial statements.
Revenue	The Company's revenues from contracts with customers (clients) are derived from offerings that include management and technology consulting services, analytics, digital solutions, engineering, mission operations, and cyber services, substantially all with the U.S. government and its agencies and, to a lesser extent, subcontractors. The Company also serves foreign governments, as well as domestic and international commercial clients. The Company performs and generates revenue under three basic types of contracts, which include cost-reimbursable contracts, time-and-materials contracts, and fixed-price contracts. Contract Estimates We recognize revenue for many of our contracts under a contract cost-based input method and require an Estimate-at-Completion (“EAC”) process, which management uses to review and monitor the progress towards the completion of our performance obligations. Under this process, management considers various inputs and assumptions related to the EAC, including, but not limited to, progress towards completion, labor costs and productivity, material and subcontractor costs, and identified risks. Estimating the total cost at the completion of our performance obligations is subjective and requires management to make assumptions about future activity and cost drivers under the contract. Changes in these estimates can occur for a variety of reasons and, if significant, may impact the profitability of the Company’s contracts. Changes in estimates related to contracts accounted for under the EAC process are recognized on a cumulative catch-up basis in the period when such changes are determinable and reasonably estimable. If the estimate of contract profitability indicates an anticipated loss on a contract, the Company recognizes the total loss at the time it is identified. For each of the three months ended June 30, 2023 and 2022, the aggregate impact of adjustments in contract estimates was not material. Disaggregation of Revenue We disaggregate our revenue from contracts with customers by contract type and by customer type, as well as by whether the Company acts as prime contractor or sub-contractor, as we believe these categories best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. The following series of tables presents our revenue disaggregated by these categories. Revenue by Contract Type: We generate revenue under the following three basic types of contracts: •Cost-Reimbursable Contracts: Cost-reimbursable contracts provide for the payment of allowable costs incurred during performance of the contract, up to a ceiling based on the amount that has been funded, plus a fixed fee or award fee. •Time-and-Materials Contracts: Under contracts in this category, we are paid a fixed hourly rate for each direct labor hour expended, and we are reimbursed for billable material costs and billable out-of-pocket expenses inclusive of allocable indirect costs. We assume the financial risk on time-and-materials contracts because our costs of performance may exceed negotiated hourly rates. •Fixed-Price Contracts: Under a fixed-price contract, we agree to perform the specified work for a predetermined price. To the extent our actual direct and allocated indirect costs decrease or increase from the estimates upon which the price was negotiated, we will generate more or less profit, respectively, or could incur a loss. Remaining performance obligations represent the transaction price of exercised contracts for which work has not yet been performed, irrespective of whether funding has or has not been authorized and appropriated as of the date of exercise. Remaining performance obligations exclude negotiated but unexercised options, the unfunded value of expired contracts, and certain variable consideration which the Company does not expect to recognize as revenue.The Company's performance obligations are typically satisfied over time and revenue is generally recognized using a cost-based input method. Fixed-price contracts are typically billed to the customer using milestone or fixed monthly payments, while cost-reimbursable-plus-fee and time-and-material contracts are typically billed to the customer at periodic intervals (e.g., monthly or weekly) as indicated by the terms of the contract. Disparities between the timing of revenue recognition and customer billings and cash collections result in net contract assets or liabilities being recognized at the end of each reporting period.Contract assets primarily consist of unbilled receivables typically resulting from revenue recognized exceeding the amount billed to the customer and right to payment is not just subject to the passage of time. Unbilled amounts represent revenues for which billings have not been presented to customers. These amounts are generally billed and collected within one year subject to various conditions including, without limitation, appropriated and available funding. Long-term unbilled receivables not anticipated to be billed and collected within one year, which are primarily related to retainage, holdbacks, and long-term rate settlements to be billed at contract closeout, are included in other long-term assets in the accompanying condensed consolidated balance sheets. Contract liabilities primarily consist of advance payments, billings in excess of costs incurred and deferred revenue. Contract assets and liabilities are reported on a net contract basis at the end of each reporting period. The Company maintains an allowance for credit losses to provide for an estimate of uncollectible receivables.

Basis of Presentation (Policies)

3 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) and should be read in conjunction with the information contained in the Company's Annual Report on Form 10-K for the year ended March 31, 2023. The interim period unaudited condensed consolidated financial statements are presented as described below. Certain information and disclosures normally required for annual financial statements have been condensed or omitted pursuant to GAAP and SEC rules and regulations. In the opinion of management, all adjustments considered necessary for fair presentation of the results of the interim periods presented have been included. The Company’s fiscal year ends on March 31 and, unless otherwise noted, references to fiscal year or fiscal are for fiscal years ended March 31. The results of operations for the three months ended June 30, 2023 are not necessarily indicative of results to be expected for the full fiscal year.

The condensed consolidated financial statements and notes of the Company include its subsidiaries, and other entities over which the Company has a controlling financial interest or where the Company is a primary beneficiary. The Company uses the equity method to account for investments in entities that it does not control if it is otherwise able to exert significant influence over the entities' operating and financial policies. Equity investments in entities over which the Company does not have the ability to exercise significant influence and whose securities do not have a readily determinable fair value are carried at cost or cost net of other-than-temporary impairments.

Certain amounts reported in the Company's prior fiscal year condensed consolidated financial statements have been reclassified to conform to the current fiscal year presentation.

Accounting Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting periods. Areas of the financial statements where estimates may have the most significant effect include the provision for claimed indirect costs, valuation and expected lives of tangible and intangible assets, impairment of long-lived assets, accrued liabilities, revenue recognition, including the accrual of indirect costs, bonus and other incentive compensation, stock-based compensation, reserves for uncertain tax positions and valuation allowances on deferred tax assets, provisions for income taxes, postretirement obligations, collectability of receivables, and loss accruals for litigation. Actual results experienced by the Company may differ materially from management's estimates.

Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“Topic 848”). The guidance is intended to provide relief for entities impacted by reference rate reform. Topic 848 contains provisions and optional accounting expedients designed to simplify requirements around the designation of hedging relationships, probability assessments of hedged forecasted transactions, and accounting for modifications of contracts that refer to the London Interbank Offered Rate (“LIBOR”) or other rates affected by reference rate reform. The guidance is elective and is effective on the date of issuance. Topic 848 is applied prospectively to contract modifications and as of the effective date for existing and new eligible hedging relationships. During the first quarter of fiscal 2024, the Company modified its interest rate swap agreements to transition from LIBOR-indexed to term SOFR-indexed periodic swap payments to align with interest payments in connection with its term SOFR-indexed debt. As such, the Company elected the optional expedients under Topic 848 which allows the cash flow hedge to continue being recognized under hedge accounting without de-designation upon a change in critical terms affected by the reference rate reform. The adoption of this guidance did not have a material impact on the condensed consolidated financial statements and disclosures.

Recent Accounting Pronouncements Not Yet Adopted

Accounting and reporting pronouncements effective after June 30, 2023 and issued through the filing date are not expected to have a material impact on the Company's condensed consolidated financial statements.

Revenue

The Company's revenues from contracts with customers (clients) are derived from offerings that include management and technology consulting services, analytics, digital solutions, engineering, mission operations, and cyber services, substantially all with the U.S. government and its agencies and, to a lesser extent, subcontractors. The Company also serves foreign governments, as well as domestic and international commercial clients. The Company performs and generates revenue under three basic types of contracts, which include cost-reimbursable contracts, time-and-materials contracts, and fixed-price contracts.

Contract Estimates

We recognize revenue for many of our contracts under a contract cost-based input method and require an Estimate-at-Completion (“EAC”) process, which management uses to review and monitor the progress towards the completion of our performance obligations. Under this process, management considers various inputs and assumptions related to the EAC, including, but not limited to, progress towards completion, labor costs and productivity, material and subcontractor costs, and identified risks. Estimating the total cost at the completion of our performance obligations is subjective and requires management to make assumptions about future activity and cost drivers under the contract. Changes in these estimates can occur for a variety of reasons and, if significant, may impact the profitability of the Company’s contracts. Changes in estimates related to contracts accounted for under the EAC process are recognized on a cumulative catch-up basis in the period when such changes are determinable and reasonably estimable. If the estimate of contract profitability indicates an anticipated loss on a contract, the Company recognizes the total loss at the time it is identified. For each of the three months ended June 30, 2023 and 2022, the aggregate impact of adjustments in contract estimates was not material.

Disaggregation of Revenue

We disaggregate our revenue from contracts with customers by contract type and by customer type, as well as by whether the Company acts as prime contractor or sub-contractor, as we believe these categories best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. The following series of tables presents our revenue disaggregated by these categories.

Revenue by Contract Type:

We generate revenue under the following three basic types of contracts:

•Cost-Reimbursable Contracts: Cost-reimbursable contracts provide for the payment of allowable costs incurred during performance of the contract, up to a ceiling based on the amount that has been funded, plus a fixed fee or award fee.

•Time-and-Materials Contracts: Under contracts in this category, we are paid a fixed hourly rate for each direct labor hour expended, and we are reimbursed for billable material costs and billable out-of-pocket expenses inclusive of allocable indirect costs. We assume the financial risk on time-and-materials contracts because our costs of performance may exceed negotiated hourly rates.

•Fixed-Price Contracts: Under a fixed-price contract, we agree to perform the specified work for a predetermined price. To the extent our actual direct and allocated indirect costs decrease or increase from the estimates upon which the price was negotiated, we will generate more or less profit, respectively, or could incur a loss.

Remaining performance obligations represent the transaction price of exercised contracts for which work has not yet been performed, irrespective of whether funding has or has not been authorized and appropriated as of the date of exercise. Remaining performance obligations exclude negotiated but unexercised options, the unfunded value of expired contracts, and certain variable consideration which the Company does not expect to recognize as revenue.The Company's performance obligations are typically satisfied over time and revenue is generally recognized using a cost-based input method. Fixed-price contracts are typically billed to the customer using milestone or fixed monthly payments, while cost-reimbursable-plus-fee and time-and-material contracts are typically billed to the customer at periodic intervals (e.g., monthly or weekly) as indicated by the terms of the contract. Disparities between the timing of revenue recognition and customer billings and cash collections result in net contract assets or liabilities being recognized at the end of each reporting period.Contract assets primarily consist of unbilled receivables typically resulting from revenue recognized exceeding the amount billed to the customer and right to payment is not just subject to the passage of time. Unbilled amounts represent revenues for which billings have not been presented to customers. These amounts are generally billed and collected within one year subject to various conditions including, without limitation, appropriated and available funding. Long-term unbilled receivables not anticipated to be billed and collected within one year, which are primarily related to retainage, holdbacks, and long-term rate settlements to be billed at contract closeout, are included in other long-term assets in the accompanying condensed consolidated balance sheets. Contract liabilities primarily consist of advance payments, billings in excess of costs incurred and deferred revenue. Contract assets and liabilities are reported on a net contract basis at the end of each reporting period. The Company maintains an allowance for credit losses to provide for an estimate of uncollectible receivables.