Booz Allen Hamilton Holding (BAH) 10-Q 30 Oct 20 2021 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Sep. 30, 2020	Oct. 27, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-34972
Entity Registrant Name	Booz Allen Hamilton Holding Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2634160
Entity Address, Address Line One	8283 Greensboro Drive,
Entity Address, City or Town	McLean,
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22102
City Area Code	703
Local Phone Number	902-5000
Title of 12(b) Security	Class A Common Stock
Trading Symbol	BAH
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		137,900,150
Entity Central Index Key	0001443646
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--03-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Current assets:
Cash and cash equivalents	$ 1,275,190	$ 741,901
Accounts receivable, net of allowance	1,467,581	1,459,471
Prepaid expenses and other current assets	68,272	126,816
Total current assets	2,811,043	2,328,188
Property and equipment, net of accumulated depreciation	201,784	208,077
Operating lease right-of-use assets	241,523	240,122
Intangible assets, net of accumulated amortization	303,769	300,987
Goodwill	1,581,160	1,581,160
Other long-term assets	145,619	135,432
Total assets	5,284,898	4,793,966
Current liabilities:
Current portion of long-term debt	77,865	177,865
Accounts payable and other accrued expenses	852,885	698,011
Accrued compensation and benefits	360,547	348,775
Operating lease liabilities	52,988	49,021
Other current liabilities	57,306	54,006
Total current liabilities	1,401,591	1,327,678
Long-term debt, net of current portion	2,315,739	2,007,979
Operating lease liabilities, net of current portion	266,236	270,266
Other long-term liabilities	329,375	331,687
Total liabilities	4,312,941	3,937,610
Commitments and contingencies (Note 18)
Stockholders’ equity:
Common stock, Class A — $0.01 par value — authorized, 600,000,000 shares; issued, 162,079,334 shares at September 30, 2020 and 161,333,973 shares at March 31, 2020; outstanding, 138,024,601 shares at September 30, 2020 and 138,719,921 shares at March 31, 2020	1,621	1,613
Treasury stock, at cost — 24,054,733 at September 30, 2020 and 22,614,052 shares at March 31, 2020	(1,003,650)	(898,095)
Additional paid-in capital	509,512	468,027
Retained earnings	1,508,206	1,330,812
Accumulated other comprehensive loss	(43,732)	(46,001)
Total stockholders’ equity	971,957	856,356
Total liabilities and stockholders’ equity	$ 5,284,898	$ 4,793,966

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Mar. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	600,000,000	600,000,000
Common stock, issued (in shares)	162,079,334	161,333,973
Common stock, outstanding (in shares)	138,024,601	138,719,921
Treasury stock (in shares)	24,054,733	22,614,052

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 2,019,185	$ 1,819,577	$ 3,975,638	$ 3,644,753
Operating costs and expenses:
Cost of revenue	942,597	843,942	1,891,499	1,684,596
Billable expenses	603,652	539,846	1,152,729	1,091,021
General and administrative expenses	244,700	244,122	490,555	478,402
Depreciation and amortization	21,015	19,632	41,747	39,653
Total operating costs and expenses	1,811,964	1,647,542	3,576,530	3,293,672
Operating income	207,221	172,035	399,108	351,081
Interest expense	(19,787)	(25,863)	(40,022)	(51,050)
Other (expense) income, net	(12,034)	2,005	(12,870)	3,976
Income before income taxes	175,400	148,177	346,216	304,007
Income tax expense	39,319	33,852	80,806	72,296
Net income	$ 136,081	$ 114,325	$ 265,410	$ 231,711
Earnings per common share (Note 4):
Basic (in dollars per share)	$ 0.98	$ 0.81	$ 1.91	$ 1.64
Diluted (in dollars per share)	$ 0.98	$ 0.80	$ 1.90	$ 1.63

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 136,081	$ 114,325	$ 265,410	$ 231,711
Other comprehensive income (loss), net of tax:
Change in unrealized gain (loss) on derivatives designated as cash flow hedges	3,664	(5,014)	2,225	(19,979)
Change in postretirement plan costs	22	16	44	50
Total other comprehensive income (loss), net of tax	3,686	(4,998)	2,269	(19,929)
Comprehensive income	$ 139,767	$ 109,327	$ 267,679	$ 211,782

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net income	$ 265,410	$ 231,711
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	41,747	39,653
Noncash lease expense	26,891	27,711
Stock-based compensation expense	25,632	15,808
Amortization of debt issuance costs	2,176	2,459
Loss on debt extinguishment	13,239	0
Losses on dispositions	25	581
Changes in assets and liabilities:
Accounts receivable, net of allowance	(8,606)	9,253
Deferred income taxes and income taxes receivable / payable	51,846	(30,322)
Prepaid expenses and other current assets	(10,279)	(16,696)
Other long-term assets	(3,664)	(95)
Accrued compensation and benefits	22,788	(28,805)
Accounts payable and other accrued expenses	154,140	34,623
Other current liabilities	2,669	2,311
Operating lease liabilities	(28,355)	(24,529)
Other long-term liabilities	10,365	3,016
Net cash provided by operating activities	566,024	266,679
Cash flows from investing activities
Purchases of property, equipment, and software	(38,084)	(59,978)
Net cash used in investing activities	(38,084)	(59,978)
Cash flows from financing activities
Proceeds from issuance of common stock	9,092	7,049
Stock option exercises	6,492	3,687
Repurchases of common stock	(116,291)	(14,658)
Cash dividends paid	(86,836)	(64,848)
Debt extinguishment costs	(8,971)	0
Repayment of debt	(488,933)	(38,962)
Proceeds from debt issuance	691,496	400,000
Other financing activities	(700)	(1,413)
Net cash provided by financing activities	5,349	290,855
Net increase in cash and cash equivalents	533,289	497,556
Cash and cash equivalents––beginning of period	741,901	283,990
Cash and cash equivalents––end of period	1,275,190	781,546
Net cash paid during the period for:
Interest	32,282	44,965
Income taxes	24,451	102,151
Supplemental disclosures of non-cash investing and financing activities
Noncash financing activities	$ 178	$ 2,110

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total		Class A Common Stock	Treasury Stock		Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]Retained Earnings
Beginning balance (shares) at Mar. 31, 2019			159,924,825	(19,896,972)
Beginning of period at Mar. 31, 2019	$ 675,366		$ 1,599	$ (711,450)		$ 401,596	$ 994,811	$ (11,190)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)			246,233
Issuance of common stock	7,049		$ 3			7,046
Stock options exercised (shares)			229,299
Stock options exercised	3,687		$ 2			3,685
Repurchase of common stock (shares)			(93,000)	(129,935)	[1]
Repurchase of common stock	(8,343)	[1]	$ (5,900)	$ (8,343)	[1]
Recognition of liability related to future restricted stock units vesting	(318)					(318)
Net income	231,711						231,711
Other comprehensive income (loss), net of tax	(19,929)							(19,929)
Dividends paid per share of common stock	(64,848)						(64,848)
Stock-based compensation expense	15,808					15,808
Ending balance (shares) at Sep. 30, 2019			160,400,357	(20,026,907)
End of period at Sep. 30, 2019	840,183		$ 1,604	$ (719,793)		427,817	1,161,674	(31,119)
Beginning balance (shares) at Jun. 30, 2019			160,244,219	(20,026,100)
Beginning of period at Jun. 30, 2019	748,823		$ 1,602	$ (719,736)		413,293	1,079,785	(26,121)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)			88,141
Issuance of common stock	3,671		$ 1			3,670
Stock options exercised (shares)			67,997
Stock options exercised	1,532		$ 1			1,531
Repurchase of common stock (shares)				(807)
Repurchase of common stock	(57)			$ (57)
Recognition of liability related to future restricted stock units vesting	(41)					(41)
Net income	114,325						114,325
Other comprehensive income (loss), net of tax	(4,998)							(4,998)
Dividends paid per share of common stock	(32,436)						(32,436)
Stock-based compensation expense	9,364					9,364
Ending balance (shares) at Sep. 30, 2019			160,400,357	(20,026,907)
End of period at Sep. 30, 2019	840,183		$ 1,604	$ (719,793)		427,817	1,161,674	(31,119)
Beginning balance (shares) at Mar. 31, 2020			161,333,973	(22,614,052)
Beginning of period at Mar. 31, 2020	856,356		$ 1,613	$ (898,095)		468,027	1,330,812	(46,001)	$ (1,180)	$ (1,180)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (shares)			443,338
Issuance of common stock	9,092		$ 5			9,087
Stock options exercised (shares)			302,023
Stock options exercised	6,492		$ 3			6,489
Repurchase of common stock (shares)			(1,300,000)	(1,440,681)	[2]
Repurchase of common stock	(105,555)	[2]	$ (96,400)	$ (105,555)	[2]
Recognition of liability related to future restricted stock units vesting	280					280
Net income	265,410						265,410
Other comprehensive income (loss), net of tax	2,269							2,269
Dividends paid per share of common stock	(86,836)						(86,836)
Stock-based compensation expense	25,629					25,629
Ending balance (shares) at Sep. 30, 2020			162,079,334	(24,054,733)
End of period at Sep. 30, 2020	971,957		$ 1,621	$ (1,003,650)		509,512	1,508,206	(43,732)
Beginning balance (shares) at Jun. 30, 2020			161,856,727	(23,659,991)
Beginning of period at Jun. 30, 2020	$ 882,467		$ 1,618	$ (973,601)		486,739	1,415,129	(47,418)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Issuance of common stock (shares)			81,482
Issuance of common stock	$ 4,669		$ 2			4,667
Stock options exercised (shares)			141,125
Stock options exercised	3,367		$ 1			3,366
Repurchase of common stock (shares)				(394,742)
Repurchase of common stock	(30,049)			$ (30,049)
Recognition of liability related to future restricted stock units vesting	(59)					(59)
Net income	136,081						136,081
Other comprehensive income (loss), net of tax	3,686							3,686
Dividends paid per share of common stock	(43,004)						(43,004)
Stock-based compensation expense	14,799					14,799
Ending balance (shares) at Sep. 30, 2020			162,079,334	(24,054,733)
End of period at Sep. 30, 2020	$ 971,957		$ 1,621	$ (1,003,650)		$ 509,512	$ 1,508,206	$ (43,732)
[1]	During the six months ended September 30, 2019, the Company purchased 93 thousand shares of the Company’s Class A Common Stock in a series of open market transactions for $5.9 million. Additionally, the Company repurchased shares during the six months ended September 30, 2019 to cover the minimum statutory withholding taxes on restricted stock units that vested on various dates during the period.
[2]	During the six months ended September 30, 2020, the Company purchased 1.3 million shares of the Company’s Class A Common Stock in a series of open market transactions for $96.4 million. Additionally, the Company repurchased shares during the six months ended September 30, 2020 to cover the minimum statutory withholding taxes on restricted stock units that vested on various dates during the period.

Condensed Consolidated Statem_5

Condensed Consolidated Statements Of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Dividends paid (in dollars per share)	$ 0.31	$ 0.23	$ 0.62		$ 0.46
Repurchase of common stock, value	$ 30,049	$ 57	$ 105,555	[1]	$ 8,343	[2]
Class A Common Stock
Repurchase of common stock (in shares)			1,300		93
Repurchase of common stock, value			$ 96,400		$ 5,900
[1]	During the six months ended September 30, 2020, the Company purchased 1.3 million shares of the Company’s Class A Common Stock in a series of open market transactions for $96.4 million. Additionally, the Company repurchased shares during the six months ended September 30, 2020 to cover the minimum statutory withholding taxes on restricted stock units that vested on various dates during the period.
[2]	During the six months ended September 30, 2019, the Company purchased 93 thousand shares of the Company’s Class A Common Stock in a series of open market transactions for $5.9 million. Additionally, the Company repurchased shares during the six months ended September 30, 2019 to cover the minimum statutory withholding taxes on restricted stock units that vested on various dates during the period.

Business Overview

Business Overview	6 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Overview	BUSINESS OVERVIEWBooz Allen Hamilton Holding Corporation, including its wholly owned subsidiaries, or the Company, we, us, and our, was incorporated in Delaware in May 2008. The Company provides management and technology consulting, analytics, engineering, digital solutions, mission operations, and cyber services to U.S. and international governments, major corporations, and not-for-profit organizations. The Company reports operating results and financial data in one reportable segment. The Company is headquartered in McLean, Virginia, with approximately 27,600 employees as of September 30, 2020

Basis of Presentation

Basis of Presentation	6 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission, or 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, 2020. 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 period 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 six months ended September 30, 2020 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 the joint ventures and partnerships over which the Company has a controlling financial interest. 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. Certain amounts reported in the Company's prior year condensed consolidated financial statements have been reclassified to conform to the current 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 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 Standards In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326). This guidance requires companies to record an allowance for expected credit losses over the contractual term of certain financial assets, including trade receivables and contract assets, and expands disclosure requirements for credit quality of financial assets. The Company adopted this standard effective April 1, 2020 using the modified retrospective method. The adoption of this standard did not have a material impact on the condensed consolidated financial statements and disclosures. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . This guidance requires a customer in a cloud computing arrangement that is a service contract to follow existing internal-use software guidance to determine which implementation costs to defer and recognize as an asset. ASU 2018-15 generally aligns the guidance on capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract with that of implementation costs incurred to develop or obtain internal-use software, including hosting arrangements that include an internal-use software license. ASU 2018-15 is effective for interim reporting periods for fiscal years beginning after December 15, 2019. The Company adopted this standard effective April 1, 2020 on a prospective basis, and adoption of this standard did not have a material impact on the condensed consolidated financial statements. In December 2019, the FASB issued ASU 2019-12 Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes . This guidance includes removal of certain exceptions to the general principles of Topic 740, and simplification in several other areas such as accounting for a franchise tax (or similar tax) that is partially based on income. The provisions of this standard are effective for years beginning after December 15, 2020, with early adoption permitted. The Company early adopted the standard effective April 1, 2020, and applied most of the relevant amendments prospectively. The Company’s adoption did not have a material impact on the condensed consolidated financial statements. 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 . This guidance contains optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other areas or transactions that are impacted by reference rate reform. The Company elected to adopt Topic 848 in fiscal 2020 and as of September 30, 2020, the Company has elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the Company’s ability to apply hedge accounting to our derivative financial instruments. The Company continues to evaluate the impact of the guidance and may apply other elections, as applicable and as allowed by Topic 848. Recent Accounting Pronouncements Not Yet Adopted Other accounting and reporting pronouncements effective after September 30, 2020 and issued through the filing date are not expected to have a material impact on the Company's condensed consolidated financial statements.

Revenue

Revenue	6 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue	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 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 under various types of contracts, which include cost-reimbursable contracts, time-and-materials contracts, and fixed-price contracts. Contract Estimates Many of our contracts recognize revenue 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 completion of 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 and six months ended September 30, 2020 and 2019, 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, customer, as well as 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. The table below presents the total revenue for each type of contract: Three Months Ended Six Months Ended 2020 2019 2020 2019 Cost-reimbursable $ 1,138,501 56 % $ 1,026,055 57 % $ 2,230,549 56 % $ 2,052,648 56 % Time-and-materials 504,663 25 % 423,605 23 % 1,007,209 25 % 844,200 23 % Fixed-price 376,021 19 % 369,917 20 % 737,880 19 % 747,905 21 % Total Revenue $ 2,019,185 100 % $ 1,819,577 100 % $ 3,975,638 100 % $ 3,644,753 100 % Revenue by Customer Type: Three Months Ended Six Months Ended 2020 2019 2020 2019 U.S. government: Defense Clients $ 1,000,340 50 % $ 845,270 47 % $ 1,931,676 49 % $ 1,704,206 47 % Intelligence Clients 396,110 19 % 405,220 22 % 803,214 20 % 824,287 22 % Civil Clients 570,213 28 % 511,012 28 % 1,128,136 28 % 1,003,045 28 % Total U.S. government 1,966,663 97 % 1,761,502 97 % 3,863,026 97 % 3,531,538 97 % Global Commercial Clients 52,522 3 % 58,075 3 % 112,612 3 % 113,215 3 % Total Revenue $ 2,019,185 100 % $ 1,819,577 100 % $ 3,975,638 100 % $ 3,644,753 100 % Revenue by Whether the Company Acts as a Prime Contractor or a Sub-Contractor: Three Months Ended Six Months Ended 2020 2019 2020 2019 Prime Contractor $ 1,880,778 93 % $ 1,676,522 92 % $ 3,684,382 93 % $ 3,349,952 92 % Sub-contractor 138,407 7 % 143,055 8 % 291,256 7 % 294,801 8 % Total Revenue $ 2,019,185 100 % $ 1,819,577 100 % $ 3,975,638 100 % $ 3,644,753 100 % Performance Obligations 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 do not include negotiated but unexercised options or the unfunded value of expired contracts. As of September 30, 2020 and March 31, 2020, the Company had $8.4 billion and $6.3 billion, respectively, of remaining performance obligations and we expect to recognize more than half of the remaining performance obligations at September 30, 2020 as revenue over the next 12 months, and approximately three quarters over the next 24 months. The remainder is expected to be recognized thereafter. Contract Balances 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 results 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. 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 doubtful accounts to provide for an estimate of uncollected receivables. Refer to Note 5 for more information on receivables recognized from contracts accounted for under Accounting Standards Codification (ASC) No. 606, Revenue from Contracts with Customers (Topic 606). The following table summarizes the contract balances recognized on the Company’s condensed consolidated balance sheets: Balance Sheet line item September 30, March 31, Contract assets: Current Accounts receivable, net of allowance 1,022,558 988,634 Long-term Other long-term assets 63,294 62,600 Total $ 1,085,852 $ 1,051,234 Contract liabilities: Advance payments, billings in excess of costs incurred and deferred revenue Other current liabilities $ 28,840 $ 26,018

Earnings Per Share

Earnings Per Share	6 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The Company computes basic and diluted earnings per share amounts based on net income for the periods presented. The Company uses the weighted-average number of common shares outstanding during the period to calculate basic earnings per share, or EPS. Diluted EPS adjusts the weighted average number of shares outstanding to include the dilutive effect of outstanding common stock options and other stock-based awards. The Company currently has outstanding shares of Class A Common Stock. Unvested Class A Restricted Common Stock holders are entitled to participate in non-forfeitable dividends or other distributions. These unvested restricted shares participated in the Company's dividends declared and were paid in the first and second quarters of fiscal 2021 and 2020. As such, EPS is calculated using the two-class method whereby earnings are reduced by distributed earnings as well as any available undistributed earnings allocable to holders of unvested restricted shares. A reconciliation of the income used to compute basic and diluted EPS for the periods presented are as follows: Three Months Ended Six Months Ended 2020 2019 2020 2019 Earnings for basic computations (1) $ 135,283 $ 113,725 $ 263,951 $ 230,492 Weighted-average common shares outstanding for basic computations 137,882,906 140,245,038 138,017,120 140,125,779 Earnings for diluted computations (1) $ 135,286 $ 113,728 $ 263,958 $ 230,499 Dilutive stock options and restricted stock 864,734 1,117,098 987,262 1,127,138 Weighted-average common shares outstanding for diluted computations 138,747,640 141,362,136 139,004,382 141,252,917 Earnings per common share Basic $ 0.98 $ 0.81 $ 1.91 $ 1.64 Diluted $ 0.98 $ 0.80 $ 1.90 $ 1.63

Accounts Receivable, Net of All

Accounts Receivable, Net of Allowance	6 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Accounts Receivable, Net of Allowance	ACCOUNTS RECEIVABLE, NET OF ALLOWANCE Accounts receivable, net of allowance consisted of the following: September 30, March 31, Current assets Accounts receivable–billed $ 449,382 $ 474,822 Accounts receivable–unbilled 1,022,558 988,634 Allowance for doubtful accounts (4,359) (3,985) Accounts receivable, net of allowance 1,467,581 1,459,471 Other long-term assets Accounts receivable–unbilled 63,294 62,600 Total accounts receivable, net $ 1,530,875 $ 1,522,071 Unbilled amounts represent revenues for which billings have not been presented to customers at quarter-end or year-end. 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. The Company recognized a (benefit) provision for doubtful accounts of $(0.09) million and $0.5 million for the three months ended September 30, 2020 and 2019, respectively, and $(0.12) million and $2.4 million for the six months ended September 30, 2020 and September 30, 2019, respectively.

Accounts Payable and Other Accr

Accounts Payable and Other Accrued Expenses	6 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Accounts Payable and Other Accrued Expenses	ACCOUNTS PAYABLE AND OTHER ACCRUED EXPENSES Accounts payable and other accrued expenses consisted of the following: September 30, March 31, Vendor payables $ 452,804 $ 432,953 Accrued expenses 400,081 265,058 Total accounts payable and other accrued expenses $ 852,885 $ 698,011 Accrued expenses consisted primarily of the Company’s provision for claimed indirect costs, which were approximately $237.5 million and $224.6 million as of September 30, 2020 and March 31, 2020, respectively. See Note 18 for further discussion of this provision.

Accrued Compensation and Benefi

Accrued Compensation and Benefits	6 Months Ended
	Sep. 30, 2020
Compensation Related Costs [Abstract]
Accrued Compensation and Benefits	ACCRUED COMPENSATION AND BENEFITS Accrued compensation and benefits consisted of the following: September 30, March 31, Bonus $ 45,024 $ 114,359 Retirement 75,548 41,604 Vacation 210,977 159,512 Other 28,998 33,300 Total accrued compensation and benefits $ 360,547 $ 348,775

Debt

Debt	6 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt	DEBT Debt consisted of the following: September 30, 2020 March 31, 2020 Interest Outstanding Interest Outstanding Term Loan A 1.65 % $ 1,326,752 2.49 % $ 1,363,739 Term Loan B 1.90 % 386,157 2.74 % 388,102 Revolver — 3.75 % 100,000 Senior Notes 3.88 % 700,000 — % — 2017 Senior Notes — % — 5.13 % 350,000 Less: Unamortized debt issuance costs and discount on debt (19,305) (15,997) Total 2,393,604 2,185,844 Less: Current portion of long-term debt (77,865) (177,865) Long-term debt, net of current portion $ 2,315,739 $ 2,007,979 Term Loans and Revolving Credit Facility On November 26, 2019 (the "Amendment Effective Date"), Booz Allen Hamilton Inc. ("Booz Allen Hamilton"), Booz Allen Hamilton Investor Corporation ("Investor"), and certain wholly-owned subsidiaries of Booz Allen Hamilton, entered into the Seventh Amendment (the "Seventh Amendment") to the Credit Agreement (as amended, the "Credit Agreement"), dated as of July 31, 2012 among Booz Allen Hamilton, Investor, certain wholly-owned subsidiaries of Booz Allen Hamilton and Bank of America, N.A., as Administrative Agent and Collateral Agent and the other lenders and financial institutions from time to time party thereto (as previously amended by the First Amendment to the Credit Agreement, dated as of August 16, 2013, the Second Amendment to the Credit Agreement, dated as of May 7, 2014, the Third Amendment to the Credit Agreement, dated as of July 13, 2016, the Fourth Amendment to the Credit Agreement, dated as of February 6, 2017, the Fifth Amendment to the Credit Agreement, dated as of March 7, 2018, and the Sixth Amendment to the Credit Agreement, dated July 23, 2018). Pursuant to the Seventh Amendment, the Company reduced the applicable margin applicable to the Term Loan B ("Term Loan B" and, together with the Term Loan A, the "Term Loans") from 2.00% to 1.75% for LIBOR loans and from 1.00% to 0.75% for base rate loans and extended the maturity of the Term Loan B to November 26, 2026. The applicable margin and maturity date applicable to the Term Loan A (the "Term Loan A") remained unchanged. Prior to the Seventh Amendment, approximately $389.0 million was outstanding under Term Loan B. Pursuant to the Seventh Amendment, certain lenders converted their existing Term Loan B loans into a new tranche of Term Loan B loans in an aggregate amount, along with Term Loan B loans advanced by certain new lenders, of approximately $389.0 million (the “New Refinancing Tranche B Term Loans”). The proceeds from the new lenders were used to prepay in full all of the existing Term Loan B loans that were not converted into the new Term Loan B tranche. Voluntary prepayments of the New Refinancing Tranche B Term Loans are permitted at any time, in minimum principal amounts, without premium or penalty, subject to a 1.00% premium payable in connection with certain repricing transactions within the first six months after the Seventh Amendment. The other terms of the New Refinancing Tranche B Term Loans are generally the same as the existing Term Loan B prior to the Seventh Amendment. As of September 30, 2020, the Credit Agreement provided Booz Allen Hamilton with a $1,326.8 million Term Loan A, a $386.2 million Term Loan B, and $500.0 million revolving credit facility (the "Revolving Credit Facility") with a sub-limit for letters of credit of $100.0 million (collectively, the "Secured Credit Facility"). As of September 30, 2020, the maturity date of Term Loan A and the termination date for the Revolving Credit Facility was July 23, 2023 and the maturity date of Term Loan B was November 26, 2026. Booz Allen Hamilton’s obligations and the guarantors’ guarantees under the Credit Agreement are secured by a first priority lien on substantially all of the assets (including capital stock of subsidiaries) of Booz Allen Hamilton, Investor, and the subsidiary guarantors, subject to certain exceptions set forth in the Credit Agreement and related documentation. Subject to specified conditions, without the consent of the then-existing lenders (but subject to the receipt of commitments), the Term Loans or the Revolving Credit Facility may be expanded (or a new term loan facility or revolving credit facility added to the existing facilities) by up to (i) the greater of (x) $627 million and (y) 100% of consolidated EBITDA of Booz Allen Hamilton, as of the end of the most recently ended four quarter period for which financial statements have been delivered pursuant to the Credit Agreement plus (ii) the aggregate principal amount under which pro forma consolidated net secured leverage remains less than or equal to 3.50:1.00. At Booz Allen Hamilton’s option, borrowings under the Secured Credit Facility bear interest based either at LIBOR (adjusted for maximum reserves, and subject to a floor of zero) for the applicable interest period or a base rate (equal to the highest of (x) the administrative agent’s prime corporate rate, (y) the overnight federal funds rate plus 0.50%, and (z) three-month LIBOR (adjusted for maximum reserves, and subject to a floor of zero) plus 1.00%), in each case plus an applicable margin, payable at the end of the applicable interest period and in any event at least quarterly. The applicable margin for Term Loan A and borrowings under the Revolving Credit Facility ranges from 1.25% to 2.00% for LIBOR loans and 0.25% to 1.00% for base rate loans, in each case based on Booz Allen Hamilton’s consolidated total net leverage ratio. The applicable margin for Term Loan B is 1.75% for LIBOR loans and 0.75% for base rate loans. Unused commitments under the Revolving Credit Facility are subject to a quarterly fee ranging from 0.20% to 0.35% based on Booz Allen Hamilton’s consolidated total net leverage ratio. Booz Allen Hamilton occasionally borrows under the Revolving Credit Facility in anticipation of cash demands. For both the three and six months ended September 30, 2020 and 2019, Booz Allen Hamilton accessed no amounts of its $500.0 million Revolving Credit Facility. As of September 30, 2020, there was no outstanding balance on the Revolving Credit Facility. As of March 31, 2020, $100.0 million was outstanding on the Revolving Credit Facility, which was repaid in June 2020. The Credit Agreement, as amended, requires quarterly principal payments of 1.25% of the stated principal amount of Term Loan A until maturity, and quarterly principal payments of 0.25% of the stated principal amount of Term Loan B until maturity. The Credit Agreement contains customary representations and warranties and customary affirmative and negative covenants. The negative covenants include limitations on the following, in each case subject to certain exceptions: (i) indebtedness and liens; (ii) mergers, consolidations or amalgamations, liquidations, wind-ups or dissolutions, and disposition of all or substantially all assets; (iii) dispositions of property; (iv) restricted payments; (v) investments; (vi) transactions with affiliates; (vii) change in fiscal periods; (viii) negative pledges; (ix) restrictive agreements; (x) line of business; and (xi) speculative hedging. The events of default include the following, in each case subject to certain exceptions: (a) failure to make required payments under the Secured Credit Facility; (b) material breaches of representations or warranties under the Secured Credit Facility; (c) failure to observe covenants or agreements under the Secured Credit Facility; (d) failure to pay or default under certain other material indebtedness; (e) bankruptcy or insolvency; (f) certain Employee Retirement Income Security Act, or ERISA events; (g) certain material judgments; (h) actual or asserted invalidity of the Guarantee and Collateral Agreements or the other security documents or failure of the guarantees or perfected liens thereunder; and (i) a change of control. In addition, Booz Allen Hamilton is required to meet certain financial covenants at each quarter end, namely Consolidated Net Total Leverage and Consolidated Net Interest Coverage Ratios. As of September 30, 2020 and March 31, 2020, Booz Allen Hamilton was in compliance with all financial covenants associated with its debt and debt-like instruments. For the three months ended September 30, 2020 and 2019, interest payments of $5.8 million and $13.9 million were made for Term Loan A and $1.9 million and $4.4 million were made for Term Loan B, respectively. For the six months ended September 30, 2020 and 2019, interest payments of $12.7 million and $27.2 million were made for Term Loan A and $4.1 million and $8.8 million were made for Term Loan B, respectively. Borrowings under the Term Loans, and if used, the Revolving Credit Facility, incur interest at a variable rate. In accordance with Booz Allen Hamilton’s risk management strategy, between April 6, 2017 and April 4, 2019, Booz Allen Hamilton executed a series of interest rate swaps. As of September 30, 2020, Booz Allen Hamilton had interest rate swaps with an aggregate notional amount of $1 billion. These instruments hedge the variability of cash outflows for interest payments on the term loan debts and Revolving Credit Facility. The Company's objectives in using cash flow hedges are to reduce volatility due to interest rate movements and to add stability to interest expense (See Note 9 to our condensed consolidated financial statements). Senior Notes On August 24, 2020, Booz Allen Hamilton issued $700.0 million aggregate principal amount of its 3.875% Senior Notes due 2028 (the “Senior Notes”) under an Indenture, dated as of August 24, 2020, among Booz Allen Hamilton, certain subsidiaries of Booz Allen Hamilton, as guarantors (the “Subsidiary Guarantors”), and Wilmington Trust, National Association as trustee (the “Trustee”), as supplemented by the First Supplemental Indenture, dated as of August 24, 2020, among Booz Allen Hamilton, the Subsidiary Guarantors and the Trustee. Each of Booz Allen Hamilton's existing and future restricted subsidiaries that guarantee its obligations under the Secured Credit Facility or certain other indebtedness guarantee the Senior Notes on a senior unsecured basis. The Senior Notes and the guarantees are Booz Allen Hamilton’s and each Subsidiary Guarantors’ senior unsecured obligations and rank equally in right of payment with all of Booz Allen Hamilton’s and the Subsidiary Guarantors’ existing and future senior indebtedness and rank senior in right of payment to any of Booz Allen Hamilton’s and the Subsidiary Guarantors’ future subordinated indebtedness. Booz Allen Hamilton may redeem some or all of the Senior Notes at any time prior to September 1, 2023, at a price equal to 100.00% of the principal amount of the Senior Notes redeemed, plus accrued and unpaid interest, if any, to (but not including) the redemption date, plus an applicable “make-whole premium.” Booz Allen Hamilton may redeem the Senior Notes at its option, in whole at any time or in part from time to time, upon certain required notice, at any time (i) on and after September 1, 2023, at a price equal to 101.94% of the principal amount of the Senior Notes, (ii) on or after September 1, 2024, at a price equal to 100.97% of the principal amount of the Senior Notes, and (iii) on September 1, 2025 and thereafter, at a price equal to 100.00% of the principal amount of the Senior Notes, in each case, plus accrued and unpaid interest, if any, to (but not including) the applicable redemption date. In addition, at any time on or prior to September 1, 2023, Booz Allen Hamilton may redeem up to 40.00% of the original aggregate principal amount of the Senior Notes with the net cash proceeds of certain equity offerings at a redemption price equal to 103.88% of the principal amount of the Senior Notes, plus accrued and unpaid interest, if any, to (but not including) the redemption date, provided that at least 50.00% of the original aggregate principal amount of the Senior Notes remains outstanding after each such redemption; and the redemption occurs within 180 days of the closing date of such equity offering. Interest is payable on the Senior Notes semi-annually on March 1 and September 1 of each year, beginning on March 1, 2021, and principal is due at maturity on September 1, 2028. In connection with the issuance of the Senior Notes, the Company recognized $9.2 million of issuance costs, which were recorded as an offset against the carrying value of debt and will be amortized to interest expense over the term of the Senior Notes. 2017 Senior Notes On April 25, 2017, Booz Allen Hamilton issued $350.0 million aggregate principal amount of its 5.125% Senior Notes due 2025 (the "2017 Senior Notes"), under an Indenture, dated as of April 25, 2017, among Booz Allen Hamilton, certain subsidiaries of Booz Allen Hamilton, as guarantors, and Wilmington Trust, National Association, as trustee, as supplemented by the First Supplemental Indenture, dated as of April 25, 2017, among Booz Allen Hamilton, certain subsidiaries of Booz Allen Hamilton, as guarantors, and Wilmington Trust, National Association, as trustee. Each of Booz Allen Hamilton's existing and future domestic restricted subsidiaries that guaranteed its obligations under the Secured Credit Facility and certain other indebtedness guaranteed the 2017 Senior Notes on a senior unsecured basis. On August 24, 2020, Booz Allen Hamilton used a portion of the net proceeds from the sale of the Senior Notes to redeem in full $350.0 million aggregate principal amount of the outstanding 2017 Senior Notes at a redemption price of 102.563% of the principal amount thereof, plus accrued and unpaid interest thereon to (but excluding) the redemption date, and to pay all fees and expenses related to the foregoing. Booz Allen Hamilton intends to use the remaining net proceeds from the sale of the Senior Notes for working capital and other general corporate purposes. For the three month ended September 30, 2020, the Company recorded $13.2 million of loss on debt extinguishment in other (expense) income, net on the Condensed Consolidated Statements of Operations, including $9.0 million of the premium paid at redemption, and write-off of the unamortized debt issuance cost of the 2017 Senior Notes. Interest on debt and debt-like instruments consisted of the following: Three Months Ended Six Months Ended 2020 2019 2020 2019 (In thousands) (In thousands) Term Loan A Interest Expense $ 5,722 $ 13,584 $ 12,640 $ 27,034 Term Loan B Interest Expense 1,894 4,232 4,108 8,652 Interest on Revolving Credit Facility — — 799 — Senior Notes Interest Expense 5,505 4,298 9,989 8,969 Deferred Payment Obligation Interest (1) — 2,011 — 4,022 Amortization of Debt Issuance Cost (DIC) and Original Issue Discount (OID) (2) 1,106 1,425 2,176 2,459 Interest Swap Expense 5,364 46 9,805 (477) Other 196 267 505 391 Total Interest Expense $ 19,787 $ 25,863 $ 40,022 $ 51,050 (1) Interest payments on the deferred payment obligation were made twice a year in January and July. The final payment was made on December 18, 2019. (2) DIC and OID on the Term Loans and senior notes are recorded as a reduction of long-term debt in the condensed consolidated balance sheet and are amortized ratably over the life of the related debt using the effective rate method. DIC on the Revolving Credit Facility is recorded as a long-term asset on the condensed consolidated balance sheet and amortized ratably over the term of the Revolving Credit Facility.

Derivatives

Derivatives	6 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES The Company utilizes derivative financial instruments to manage interest rate risk related to its variable rate debt. The Company’s objectives in using these interest rate derivatives, which were designated as cash flow hedges, are to manage its exposure to interest rate movements and reduce volatility of interest expense. The aggregate notional amount of all interest rate swap agreements was $1.0 billion as of September 30, 2020. The swaps have staggered maturities, ranging from June 30, 2021 to June 30, 2025. These swaps mature within the last tranche of the Company's floating rate debt (November 26, 2026). The floating-to-fixed interest rate swaps involve the exchange of variable interest amounts from a counterparty for the Company making fixed-rate interest payments over the life of the agreements without exchange of the underlying notional amount and effectively convert a portion of the variable rate debt into fixed interest rate debt. Derivative instruments are recorded in the condensed consolidated balance sheet on a gross basis at estimated fair value. As of September 30, 2020, $19.8 million and $33.8 million were classified as other current liabilities and other long-term liabilities, respectively, on the condensed consolidated balance sheet. As of March 31, 2020, $18.8 million and $37.8 million were classified as other current liabilities, and other long-term liabilities, respectively, on the condensed consolidated balance sheet. For interest rate swaps designated as cash flow hedges, the changes in the fair value of derivatives is recorded in Accumulated Other Comprehensive Loss, or AOCL, net of taxes, and is subsequently reclassified into interest expense in the period that the hedged forecasted interest payments are made on the Company's variable-rate debt. The effect of derivative instruments on the accompanying condensed consolidated financial statements for the three and six months ended September 30, 2020 and 2019 is as follows: Three Months Ended September 30, Derivatives in Cash Flow Hedging Relationships Location of Gain or Loss Recognized in Income on Derivatives Amount of Gain or (Loss) Recognized in AOCL on Derivatives Amount of Gain or (Loss) Reclassified from AOCL into Income Interest Expense on Condensed Consolidated Statements of Operations 2020 2019 2020 2019 2020 2019 Interest rate swaps Interest expense $ (408) $ (6,837) $ (5,364) $ (46) $ (19,787) $ (25,863) Six Months Ended September 30, Derivatives in Cash Flow Hedging Relationships Location of Gain or Loss Recognized in Income on Derivatives Amount of (Loss) or Gain Recognized in AOCL on Derivatives Amount of (Loss) or Gain Reclassified from AOCL into Income Interest Expense on Condensed Consolidated Statements of Operations 2020 2019 2020 2019 2020 2019 Interest rate swaps Interest expense $ (6,795) $ (26,585) $ (9,805) $ 477 $ (40,022) $ (51,050) Over the next 12 months, the Company estimates that $20.0 million will be reclassified as an increase to interest expense. Cash flows associated with periodic settlements of interest rate swaps will be classified as operating activities in the condensed consolidated statement of cash flows. The Company is subject to counterparty risk in connection with its interest rate swap derivative contracts. Credit risk related to a derivative financial instrument represents the possibility that the counterparty will not fulfill the terms of the contract. The Company mitigates this credit risk by entering into agreements with credit-worthy counterparties and regularly reviews its credit exposure and the creditworthiness of the counterparties.

Leases

Leases	6 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	LEASES The Company’s total lease cost is recorded primarily within general and administrative expenses on the condensed consolidated statement of operations and consisted of the following: Three Months Ended Six Months Ended 2020 2019 2020 2019 Operating lease cost $ 17,214 $ 17,760 $ 34,341 $ 35,720 Short-term lease cost 1,426 2,333 3,027 4,750 Variable lease cost 3,281 3,016 6,815 5,578 Total operating lease costs $ 21,921 $ 23,109 $ 44,183 $ 46,048 Future minimum operating lease payments for noncancelable operating leases as of September 30, 2020 are as follows: Fiscal Year Ending Operating Lease Payments Remainder of 2021 $ 30,050 2022 70,358 2023 67,896 2024 56,728 2025 52,177 Thereafter 92,226 Total future lease payments 369,435 Less: imputed interest (50,211) Total lease liabilities $ 319,224 Supplemental cash flow information related to leases was as follows: Six Months Ended 2020 2019 Cash paid for amounts included in the measurement of lease liabilities $ 35,594 $ 32,472 Operating lease liabilities arising from obtaining ROU assets (1) 28,292 9,681 (1) Includes all noncash increases and decreases arising from new or remeasured operating lease arrangements Other information related to leases was as follows: September 30, 2020 Weighted average remaining lease term (in years) 5.71 Weighted average discount rate 4.75 %

Income Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company’s effective income tax rates were 22.4% and 22.8% for the three months ended September 30, 2020 and 2019, respectively, and 23.3% and 23.8% for the six months ended September 30, 2020 and 2019, respectively. The effective tax rates of 22.4% and 23.3% for the three and six months ended September 30, 2020 differ from the federal statutory rate of 21.0% primarily due to the inclusion of state and foreign income taxes and permanent rate differences, which are predominantly related to certain executive compensation, partially offset by research and development tax credits and excess tax benefits for employee share-based compensation. The Company is currently contesting tax assessments from the District of Columbia Office of Tax and Revenue for fiscal years 2013 through 2015 at various stages of applicable administrative and judicial processes, with a combined amount at issue of approximately $11.7 million, net of associated federal tax benefits as of September 30, 2020. The Company has taken similar tax positions with respect to subsequent fiscal years, net of expiring statute of limitations, totaling in aggregate $32.5 million. As of September 30, 2020, the Company does not maintain reserves for any uncertain tax positions related to the contested tax benefits or the similar tax positions taken in the subsequent fiscal years. Given the recoverable nature of the state tax expense, the Company does not believe that the resolution of these matters will have a material adverse effect on its results of operations, cash flows or financial condition. The Company maintained reserves for uncertain tax positions of $65.9 million and $56.1 million as of September 30, 2020 and March 31, 2020, respectively, which are included in other long-term liabilities in the accompanying condensed consolidated balance sheets. As of September 30, 2020, the Company maintained reserves for uncertain tax positions of $54.1 million relating to research and development tax credits and $10.2 million relating to the acquisition of eGov Holdings, Inc. (d/b/a Aquilent) in the fourth quarter of fiscal 2017 for pre-acquisition period tax return uncertain tax positions.

Other Long-Term Liabilities

Other Long-Term Liabilities	6 Months Ended
	Sep. 30, 2020
Other Liabilities Disclosure [Abstract]
Other Long-Term Liabilities	OTHER LONG-TERM LIABILITIES Other long-term liabilities consisted of the following: September 30, March 31, Postretirement benefit obligations 126,502 124,375 Other (1) 202,873 207,312 Total other long-term liabilities $ 329,375 $ 331,687

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Defined Contribution Plan The Company sponsors the Employees’ Capital Accumulation Plan, or ECAP, which is a qualified defined contribution plan that covers eligible U.S. and certain international employees. ECAP provides for distributions to participants by reason of retirement, death, disability, or termination of employment. The Company provides an annual matching contribution of up to 6% of eligible annual compensation. Total expenses recognized under ECAP were $40.2 million and $36.2 million for the three months ended September 30, 2020 and 2019, respectively, and $81.3 million and $73.1 million for the six months ended September 30, 2020 and 2019, respectively. The Company-paid contributions were $24.6 million and $22.1 million for the three months ended September 30, 2020 and 2019, respectively, and $47.8 million and $42.0 million for the six months ended September 30, 2020 and 2019, respectively. Defined Benefit Plan and Other Postretirement Benefit Plans The Company provides postretirement healthcare benefits to former officers under a medical indemnity insurance plan, with premiums paid by the Company. This plan is referred to as the Officer Medical Plan. The Company also established a non-qualified defined benefit plan for all officers in May 1995, or the Retired Officers' Bonus Plan, which pays a lump-sum amount of $10,000 per year of service as an officer, provided the officer meets retirement vesting requirements. In addition, the Company provides a fixed annual allowance after retirement to cover financial counseling, tax preparation and other financial or wellness expenses. The Retired Officers' Bonus Plan is not salary related, but rather is based primarily on years of service. The Company also provides for a one-time lump sum retirement payment of one month’s salary when a vice-president retires from the Company. This is referred to as the Retired Vice-President Bonus Plan. The components of net postretirement medical expense for the Officer Medical Plan were as follows: Three Months Ended Six Months Ended 2020 2019 2020 2019 Service cost $ 1,414 $ 1,239 $ 2,828 $ 2,478 Interest cost 1,059 1,215 2,118 2,430 Total postretirement medical expense $ 2,473 $ 2,454 $ 4,946 $ 4,908 The service cost component of net periodic benefit cost is included in cost of revenue and general and administrative expenses, and the non-service cost components of net periodic benefit cost (interest cost and net actuarial loss) is included as part of Other (expense) income, net in the accompanying condensed consolidated statements of operations. As of September 30, 2020 and March 31, 2020, the unfunded status of the post-retirement medical plan was $122.3 million and $119.6 million, respectively, which is included in other long-term liabilities in the accompanying condensed consolidated balance sheets. Long-term Disability Benefits The Company offers medical and dental benefits to inactive employees (and their eligible dependents) on long-term disability. These benefits do not vary with an employee's years of service; therefore, the Company is required to accrue the costs of the benefits at the date the inactive employee becomes disability eligible and elects to participate in the benefit. The accrued cost for such benefits is calculated using an actuarial estimate. The accrued cost for these benefits was $10.7 million at both September 30, 2020 and March 31, 2020, and is presented in other long-term liabilities in the accompanying condensed consolidated balance sheets. Deferred Compensation Plan The Company established a non-qualified deferred compensation plan (the "Plan") for certain executives and other highly compensated employees that was effective in fiscal 2018. Pursuant to the Plan, participants are eligible to defer up to 100% of their incentive cash compensation on a tax deferred basis in excess of the IRS limits imposed on 401(k) plans. The assets of the plan are held in a consolidated trust and are subject to the claims of the Company's general creditors under federal and state laws in the event of insolvency. Consequently, the trust qualifies as a Rabbi trust for income tax purposes. The fair values of plan investments and obligations at September 30, 2020 and March 31, 2020 were $12.9 million and $5.9 million, respectively, and were recorded in other long-term assets and in other long-term liabilities, respectively, in the condensed consolidated balance sheets. Adjustments to the fair value of the plan investments and obligations are recorded in operating expenses.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Accumulated Other Comprehensive Loss	ACCUMULATED OTHER COMPREHENSIVE LOSS All amounts recorded in other comprehensive loss are related to the Company's post-retirement plans and interest rate swaps designated as cash flow hedges. The following table shows the changes in accumulated other comprehensive loss, net of tax: Three Months Ended September 30, 2020 Six Months Ended September 30, 2020 Post-retirement plans Derivatives designated as cash flow hedges Totals Post-retirement plans Derivatives designated as cash flow hedges Totals Beginning of period $ (4,105) $ (43,313) $ (47,418) $ (4,127) $ (41,874) $ (46,001) Other comprehensive loss before reclassifications (1) — (301) (301) — (5,023) (5,023) Amounts reclassified from accumulated other comprehensive loss 22 3,965 3,987 44 7,248 7,292 Net current-period other comprehensive income 22 3,664 3,686 44 2,225 2,269 End of period $ (4,083) $ (39,649) $ (43,732) $ (4,083) $ (39,649) $ (43,732) (1) Changes in other comprehensive income (loss) before reclassification for derivatives designated as cash flow hedges are recorded net of tax benefits of $0.1 million and $1.8 million for the three and six months ended September 30, 2020, respectively. Three Months Ended September 30, 2019 Six Months Ended September 30, 2019 Post-retirement plans Derivatives designated as cash flow hedges Totals Post-retirement plans Derivatives designated as cash flow hedges Totals Beginning of period $ (9,034) $ (17,087) $ (26,121) $ (9,068) $ (2,122) $ (11,190) Other comprehensive loss before reclassifications (2) — (5,048) (5,048) — (19,627) (19,627) Amounts reclassified from accumulated other comprehensive loss 16 34 50 50 (352) (302) Net current-period other comprehensive income (loss) 16 (5,014) (4,998) 50 (19,979) (19,929) End of period $ (9,018) $ (22,101) $ (31,119) $ (9,018) $ (22,101) $ (31,119) (2) Changes in other comprehensive loss before reclassification for derivatives designated as cash flow hedges are recorded net of tax benefits of $1.8 million and $7.0 million for the three and six months ended September 30, 2019, respectively. The following table presents the reclassifications out of accumulated other comprehensive loss to net income: Three Months Ended Six Months Ended 2020 2019 2020 2019 Amounts reclassified from accumulated other comprehensive loss: Post-retirement plans (Note 13): Amortization of net actuarial loss included in net periodic benefit cost $ 28 $ 22 $ 57 $ 66 Tax (benefit) expense (6) (6) (13) (16) Net of tax $ 22 $ 16 $ 44 $ 50 Derivatives designated as cash flow hedges (Note 9): Reclassification of hedge loss (gain) $ 5,364 $ 46 $ 9,805 $ (477) Tax (benefit) expense (1,399) (12) (2,557) 125 Net of tax $ 3,965 $ 34 $ 7,248 $ (352)

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION The following table summarizes stock-based compensation expense recognized in the condensed consolidated statements of operations: Three Months Ended Six Months Ended 2020 2019 2020 2019 Cost of revenue $ 5,769 $ 2,538 $ 10,267 $ 4,472 General and administrative expenses 9,030 6,826 15,365 11,336 Total $ 14,799 $ 9,364 $ 25,632 $ 15,808 The following table summarizes the total stock-based compensation expense recognized in the condensed consolidated statements of operations by the following types of equity awards; Three Months Ended Six Months Ended 2020 2019 2020 2019 Equity Incentive Plan Options $ 684 $ 722 $ 1,130 $ 1,207 Restricted Stock Awards $ 14,115 8,642 24,502 14,601 Total $ 14,799 $ 9,364 $ 25,632 $ 15,808 As of September 30, 2020, there was $65.9 million of total unrecognized compensation cost related to unvested stock-based compensation agreements. The unrecognized compensation cost as of September 30, 2020 is expected to be fully amortized over the next 4.5 years. Absent the effect of accelerating stock compensation cost for any departures of employees who may continue to vest in their equity awards, the following table summarizes the unrecognized compensation cost and the weighted-average period the cost is expected to be amortized. September 30, 2020 Unrecognized Compensation Cost Weighted Average Remaining Period to be Recognized (in years) Equity Incentive Plan Options $ 4,972 3.79 Restricted Stock Awards 60,963 1.87 Total $ 65,935 Equity Incentive Plan As of September 30, 2020, there were 1,617,665 EIP options outstanding, of which 746,866 were unvested. During the three months ended September 30, 2020, the Board of Directors granted 159,939 restricted stock units to certain employees of the Company and granted 20,829 shares of Class A Restricted Common Stock to members of the Board of Directors. The aggregate value of these awards was $13.8 million based on the grant date stock price, which ranged from $75.11 to $87.38. Employee Stock Purchase Plan For the quarterly offering period that closed on September 30, 2020, 59,214 Class A Common Stock shares were purchased by employees under the Company's Employee Stock Purchase Plan, or ESPP. Since the program's inception, 2,778,872 shares have been purchased by employees.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The accounting standard for fair value measurements establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows: observable inputs such as quoted prices in active markets (Level 1); inputs other than quoted prices in active markets that are observable either directly or indirectly (Level 2); and unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions (Level 3). A financial instrument's level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The financial instruments measured at fair value in the accompanying condensed consolidated balance sheets consist of the following: Recurring Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Long-term deferred compensation plan asset (1) 12,913 — — 12,913 Total Assets $ 12,913 $ — $ — $ 12,913 Liabilities: Contingent consideration liability (2) $ — $ — $ 1,223 1,223 Current derivative instruments (3) — 19,820 — 19,820 Long-term derivative instruments (3) — 33,819 — 33,819 Long-term deferred compensation plan liability (1) 12,913 — — 12,913 Total Liabilities $ 12,913 $ 53,639 $ 1,223 $ 67,775 Recurring Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Long-term deferred compensation plan asset (1) 5,879 — — 5,879 Total Assets $ 5,879 $ — $ — $ 5,879 Liabilities: Contingent consideration liability (2) $ — $ — $ 1,224 $ 1,224 Current derivative instruments (3) — 18,831 — 18,831 Long-term derivative instruments (3) — 37,819 — 37,819 Long-term deferred compensation plan liability (1) 5,879 — — 5,879 Total Liabilities $ 5,879 $ 56,650 $ 1,224 $ 63,753 (1) Investments in this category consist primarily of mutual funds whose fair values are determined by reference to the quoted market price per unit in active markets multiplied by the number of units held without consideration of transaction costs. These assets represent investments held in a consolidated trust to fund the Company's non-qualified deferred compensation plan and are recorded in other long-term assets and other long-term liabilities on our condensed consolidated balance sheets. (2) The Company recognized a contingent consideration liability of $3.6 million in connection with its acquisition of Aquilent in fiscal 2017. As of both September 30, 2020 and March 31, 2020, the estimated fair value of the contingent consideration liability was $1.2 million, and was valued using probability-weighted cash flows, which is based on the use of Level 3 fair value measurement inputs. (3) The Company’s interest rate swaps are considered over-the-counter derivatives and fair value is estimated based on the present value of future cash flows using a model-derived valuation that uses Level 2 observable inputs such as interest rate yield curves. See Note 9 to the condensed consolidated financial statements for further discussion on the Company’s derivative instruments designated as cash flow hedges. The fair value of the Company's cash and cash equivalents, which are Level 1 inputs, approximated its carrying values at September 30, 2020 and March 31, 2020. The fair value of the Company's debt instruments approximated its carrying value at September 30, 2020 and March 31, 2020. The fair value of debt is determined using quoted prices or other market information obtained from recent trading activity of each debt tranche in markets that are not active (Level 2 inputs). The fair value is corroborated by prices derived from the interest rate spreads of recently completed leveraged loan transactions of a similar credit profile, industry, and terms to that of the Company. The fair value of the Senior Notes is determined using quoted prices or other market information obtained from recent trading activity in the high-yield bond market (Level 2 inputs).

Related-Party Transactions

Related-Party Transactions	6 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Related-Party Transactions	RELATED-PARTY TRANSACTIONS Two of our directors currently serve on the board of directors of a subcontractor to which the Company subcontracted $21.7 million and $15.6 million of services for the three months ended September 30, 2020 and 2019, respectively, and $45.0 million and $39.8 million for the six months ended September 30, 2020 and 2019, respectively.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Letters of Credit and Third-Party Guarantees As of September 30, 2020 and March 31, 2020, the Company was contingently liable under open standby letters of credit and bank guarantees issued by our banks in favor of third parties that totaled $11.3 million and $9.7 million, respectively. These letters of credit and bank guarantees primarily support insurance and bid and performance obligations. At both September 30, 2020 and March 31, 2020, approximately $0.9 million of these instruments reduced the available borrowings under the Revolving Credit Facility. The remainder is guaranteed under a separate $20.0 million facility, originally established in fiscal 2015 and most recently increased to $20.0 million in the first quarter of fiscal 2021, of which $9.6 million and $6.2 million were available to the Company at September 30, 2020 and March 31, 2020, respectively. Government Contracting Matters - Provision for Claimed Indirect Costs For both the three months ended September 30, 2020 and 2019, approximately 97% of the Company's revenue was generated from contracts where the end user was an agency or department of the U.S. government, including contracts where the Company performed either as a prime contractor or subcontractor, and regardless of the geographic location in which the work was performed. For both the six months ended September 30, 2020 and 2019, approximately 97% of the Company's revenue was generated from such contracts. U.S. government contracts and subcontracts are subject to extensive legal and regulatory requirements. From time to time and in the ordinary course of business, agencies of the U.S. government audit our claimed indirect costs and conduct inquiries and investigations of our business practices with respect to government contracts to determine whether the Company’s operations are conducted in accordance with these requirements and the terms of the relevant contracts. U.S. government agencies, including the Defense Contract Audit Agency (DCAA), routinely audit our claimed indirect costs for compliance with the Cost Accounting Standards and the Federal Acquisition Regulation. These agencies also conduct reviews and investigations and make inquiries regarding our accounting and other systems in connection with our performance and business practices with respect to our government contracts and subcontracts. U.S. government audits, inquiries, or investigations of the Company, whether related to the Company's U.S. government contracts or subcontracts or conducted for other reasons, could result in administrative, civil, or criminal liabilities, including withholding of payments, suspension of payments, repayments, fines, or penalties being imposed upon the Company, or could lead to suspension or debarment from future U.S. government contracting. Management believes it has recorded the appropriate provision for claimed indirect costs for any audit, inquiry, or investigation of which it is aware that may be subject to any reductions and/or penalties. As of September 30, 2020 and March 31, 2020, the Company had recorded liabilities of approximately $237.5 million and $224.6 million, respectively, for estimated adjustments to claimed indirect costs based on its historical DCAA audit results, including the final resolution of such audits with the Defense Contract Management Agency, for claimed indirect costs incurred subsequent to fiscal 2011, and for contracts not yet closed that are subject to audit and final resolution. Litigation Our performance under U.S. government contracts and compliance with the terms of those contracts and applicable laws and regulations are subject to continuous audit, review, and investigation by the U.S. government, which may include such investigative techniques as subpoenas or civil investigative demands. Given the nature of our business, these audits, reviews, and investigations may focus, among other areas, on various aspects of procurement integrity, labor time reporting, sensitive and/or classified information access and control, executive compensation, and post government employment restrictions. We are not always aware of our status in such matters, but we are currently aware of certain pending audits and investigations involving labor time reporting, procurement integrity, and classified information access. In addition, from time to time, we are also involved in legal proceedings and investigations arising in the ordinary course of business, including those relating to employment matters, relationships with clients and contractors, intellectual property disputes, and other business matters. These legal proceedings seek various remedies, including claims for monetary damages in varying amounts, none of which are considered material, or are unspecified as to amount. Although the outcome of any such matter is inherently uncertain and may be materially adverse, based on current information, we do not expect any of the currently ongoing audits, reviews, investigations, or litigation to have a material adverse effect on our financial condition and results of operations. As of September 30, 2020 and March 31, 2020, there were no material amounts accrued in the condensed consolidated financial statements related to these proceedings. On June 7, 2017, Booz Allen Hamilton Inc. was informed that the U.S. Department of Justice (DOJ) is conducting a civil and criminal investigation of the Company. In connection with the investigation, the DOJ has requested information from the Company relating to certain elements of the Company’s cost accounting and indirect cost charging practices with the U.S. government. Since learning of the investigation, the Company has engaged a law firm experienced in these matters to represent the Company in connection with this matter and respond to the government's requests. As is commonly the case with this type of matter, the Company has also been in contact with other regulatory agencies and bodies, including the SEC, which notified the Company that it is conducting an investigation that the Company believes relates to the matters that are also the subject of the DOJ's investigation. The Company may receive additional regulatory or governmental inquiries related to the matters that are the subject of the DOJ's investigation. In accordance with the Company's practice, the Company is cooperating with all relevant government parties. The total cost associated with these matters will depend on many factors, including the duration of these matters and any related findings. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with these matters. On June 19, 2017, a purported stockholder of the Company filed a putative class action lawsuit in the United States District Court for the Eastern District of Virginia styled Langley v. Booz Allen Hamilton Holding Corp., No. 17-cv-00696 naming the Company, its Chief Executive Officer and its Chief Financial Officer as defendants purportedly on behalf of all purchasers of the Company’s securities from May 19, 2016 through June 15, 2017. On September 5, 2017, the court named two lead plaintiffs, and on October 20, 2017, the lead plaintiffs filed a consolidated amended complaint. The complaint asserts claims under Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 promulgated thereunder, alleging misrepresentations or omissions by the Company purporting to relate to matters that are the subject of the DOJ investigation described above. The plaintiffs seek to recover from the Company and the individual defendants an unspecified amount of damages. The Company believes the suit lacks merit and intends to defend against the lawsuit. Motions to dismiss were argued on January 12, 2018, and on February 8, 2018, the court dismissed the amended complaint in its entirety without prejudice. At this stage of the lawsuit, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with the lawsuit. On November 13, 2017, a Verified Shareholder Derivative Complaint was filed in the United States District Court for the District of Delaware styled Celine Thum v. Rozanski et al., C.A. No. 17-cv-01638, naming the Company as a nominal defendant and numerous current and former officers and directors as defendants. The complaint asserts claims for breach of fiduciary duties, unjust enrichment, waste of corporate assets, abuse of control, gross mismanagement, and violations of Sections 14(a), 10(b) and 20(a) of the Exchange Act, purportedly relating to matters that are the subject of the DOJ investigation described above. The parties have stipulated to a stay of the proceedings pending the outcome of the securities litigation (described above), which the court so ordered on January 24, 2018. On December 12, 2019, the court ordered that the stay remain in effect and ordered the parties to submit periodic status reports. On May 27, 2020, the parties submitted status reports stating that plaintiff believes the stay should remain in effect and defendants do not object to the stay remaining in effect. At this stage of the lawsuit, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with the lawsuit.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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 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 Standards and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Standards In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326). This guidance requires companies to record an allowance for expected credit losses over the contractual term of certain financial assets, including trade receivables and contract assets, and expands disclosure requirements for credit quality of financial assets. The Company adopted this standard effective April 1, 2020 using the modified retrospective method. The adoption of this standard did not have a material impact on the condensed consolidated financial statements and disclosures. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . This guidance requires a customer in a cloud computing arrangement that is a service contract to follow existing internal-use software guidance to determine which implementation costs to defer and recognize as an asset. ASU 2018-15 generally aligns the guidance on capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract with that of implementation costs incurred to develop or obtain internal-use software, including hosting arrangements that include an internal-use software license. ASU 2018-15 is effective for interim reporting periods for fiscal years beginning after December 15, 2019. The Company adopted this standard effective April 1, 2020 on a prospective basis, and adoption of this standard did not have a material impact on the condensed consolidated financial statements. In December 2019, the FASB issued ASU 2019-12 Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes . This guidance includes removal of certain exceptions to the general principles of Topic 740, and simplification in several other areas such as accounting for a franchise tax (or similar tax) that is partially based on income. The provisions of this standard are effective for years beginning after December 15, 2020, with early adoption permitted. The Company early adopted the standard effective April 1, 2020, and applied most of the relevant amendments prospectively. The Company’s adoption did not have a material impact on the condensed consolidated financial statements. 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 . This guidance contains optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other areas or transactions that are impacted by reference rate reform. The Company elected to adopt Topic 848 in fiscal 2020 and as of September 30, 2020, the Company has elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the Company’s ability to apply hedge accounting to our derivative financial instruments. The Company continues to evaluate the impact of the guidance and may apply other elections, as applicable and as allowed by Topic 848. Recent Accounting Pronouncements Not Yet Adopted Other accounting and reporting pronouncements effective after September 30, 2020 and issued through the filing date are not expected to have a material impact on the Company's condensed consolidated financial statements.

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The table below presents the total revenue for each type of contract: Three Months Ended Six Months Ended 2020 2019 2020 2019 Cost-reimbursable $ 1,138,501 56 % $ 1,026,055 57 % $ 2,230,549 56 % $ 2,052,648 56 % Time-and-materials 504,663 25 % 423,605 23 % 1,007,209 25 % 844,200 23 % Fixed-price 376,021 19 % 369,917 20 % 737,880 19 % 747,905 21 % Total Revenue $ 2,019,185 100 % $ 1,819,577 100 % $ 3,975,638 100 % $ 3,644,753 100 % Revenue by Customer Type: Three Months Ended Six Months Ended 2020 2019 2020 2019 U.S. government: Defense Clients $ 1,000,340 50 % $ 845,270 47 % $ 1,931,676 49 % $ 1,704,206 47 % Intelligence Clients 396,110 19 % 405,220 22 % 803,214 20 % 824,287 22 % Civil Clients 570,213 28 % 511,012 28 % 1,128,136 28 % 1,003,045 28 % Total U.S. government 1,966,663 97 % 1,761,502 97 % 3,863,026 97 % 3,531,538 97 % Global Commercial Clients 52,522 3 % 58,075 3 % 112,612 3 % 113,215 3 % Total Revenue $ 2,019,185 100 % $ 1,819,577 100 % $ 3,975,638 100 % $ 3,644,753 100 % Revenue by Whether the Company Acts as a Prime Contractor or a Sub-Contractor: Three Months Ended Six Months Ended 2020 2019 2020 2019 Prime Contractor $ 1,880,778 93 % $ 1,676,522 92 % $ 3,684,382 93 % $ 3,349,952 92 % Sub-contractor 138,407 7 % 143,055 8 % 291,256 7 % 294,801 8 % Total Revenue $ 2,019,185 100 % $ 1,819,577 100 % $ 3,975,638 100 % $ 3,644,753 100 %
Summary of Contract Balances	The following table summarizes the contract balances recognized on the Company’s condensed consolidated balance sheets: Balance Sheet line item September 30, March 31, Contract assets: Current Accounts receivable, net of allowance 1,022,558 988,634 Long-term Other long-term assets 63,294 62,600 Total $ 1,085,852 $ 1,051,234 Contract liabilities: Advance payments, billings in excess of costs incurred and deferred revenue Other current liabilities $ 28,840 $ 26,018

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Reconciliation of the income used to compute basic and diluted EPS	A reconciliation of the income used to compute basic and diluted EPS for the periods presented are as follows: Three Months Ended Six Months Ended 2020 2019 2020 2019 Earnings for basic computations (1) $ 135,283 $ 113,725 $ 263,951 $ 230,492 Weighted-average common shares outstanding for basic computations 137,882,906 140,245,038 138,017,120 140,125,779 Earnings for diluted computations (1) $ 135,286 $ 113,728 $ 263,958 $ 230,499 Dilutive stock options and restricted stock 864,734 1,117,098 987,262 1,127,138 Weighted-average common shares outstanding for diluted computations 138,747,640 141,362,136 139,004,382 141,252,917 Earnings per common share Basic $ 0.98 $ 0.81 $ 1.91 $ 1.64 Diluted $ 0.98 $ 0.80 $ 1.90 $ 1.63

Accounts Receivable, Net of A_2

Accounts Receivable, Net of Allowance (Tables)	6 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Schedule of Accounts Receivable, Net of Allowance	Accounts receivable, net of allowance consisted of the following: September 30, March 31, Current assets Accounts receivable–billed $ 449,382 $ 474,822 Accounts receivable–unbilled 1,022,558 988,634 Allowance for doubtful accounts (4,359) (3,985) Accounts receivable, net of allowance 1,467,581 1,459,471 Other long-term assets Accounts receivable–unbilled 63,294 62,600 Total accounts receivable, net $ 1,530,875 $ 1,522,071

Accounts Payable and Other Ac_2

Accounts Payable and Other Accrued Expenses (Tables)	6 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable and other accrued expenses consisted of the following: September 30, March 31, Vendor payables $ 452,804 $ 432,953 Accrued expenses 400,081 265,058 Total accounts payable and other accrued expenses $ 852,885 $ 698,011

Accrued Compensation and Bene_2

Accrued Compensation and Benefits (Tables)	6 Months Ended
	Sep. 30, 2020
Compensation Related Costs [Abstract]
Schedule of accrued compensation and benefits	Accrued compensation and benefits consisted of the following: September 30, March 31, Bonus $ 45,024 $ 114,359 Retirement 75,548 41,604 Vacation 210,977 159,512 Other 28,998 33,300 Total accrued compensation and benefits $ 360,547 $ 348,775

Debt (Tables)

Debt (Tables)	6 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Debt	Debt consisted of the following: September 30, 2020 March 31, 2020 Interest Outstanding Interest Outstanding Term Loan A 1.65 % $ 1,326,752 2.49 % $ 1,363,739 Term Loan B 1.90 % 386,157 2.74 % 388,102 Revolver — 3.75 % 100,000 Senior Notes 3.88 % 700,000 — % — 2017 Senior Notes — % — 5.13 % 350,000 Less: Unamortized debt issuance costs and discount on debt (19,305) (15,997) Total 2,393,604 2,185,844 Less: Current portion of long-term debt (77,865) (177,865) Long-term debt, net of current portion $ 2,315,739 $ 2,007,979
Schedule of Interest Expense	Interest on debt and debt-like instruments consisted of the following: Three Months Ended Six Months Ended 2020 2019 2020 2019 (In thousands) (In thousands) Term Loan A Interest Expense $ 5,722 $ 13,584 $ 12,640 $ 27,034 Term Loan B Interest Expense 1,894 4,232 4,108 8,652 Interest on Revolving Credit Facility — — 799 — Senior Notes Interest Expense 5,505 4,298 9,989 8,969 Deferred Payment Obligation Interest (1) — 2,011 — 4,022 Amortization of Debt Issuance Cost (DIC) and Original Issue Discount (OID) (2) 1,106 1,425 2,176 2,459 Interest Swap Expense 5,364 46 9,805 (477) Other 196 267 505 391 Total Interest Expense $ 19,787 $ 25,863 $ 40,022 $ 51,050 (1) Interest payments on the deferred payment obligation were made twice a year in January and July. The final payment was made on December 18, 2019. (2) DIC and OID on the Term Loans and senior notes are recorded as a reduction of long-term debt in the condensed consolidated balance sheet and are amortized ratably over the life of the related debt using the effective rate method. DIC on the Revolving Credit Facility is recorded as a long-term asset on the condensed consolidated balance sheet and amortized ratably over the term of the Revolving Credit Facility.

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The effect of derivative instruments on the accompanying condensed consolidated financial statements for the three and six months ended September 30, 2020 and 2019 is as follows: Three Months Ended September 30, Derivatives in Cash Flow Hedging Relationships Location of Gain or Loss Recognized in Income on Derivatives Amount of Gain or (Loss) Recognized in AOCL on Derivatives Amount of Gain or (Loss) Reclassified from AOCL into Income Interest Expense on Condensed Consolidated Statements of Operations 2020 2019 2020 2019 2020 2019 Interest rate swaps Interest expense $ (408) $ (6,837) $ (5,364) $ (46) $ (19,787) $ (25,863) Six Months Ended September 30, Derivatives in Cash Flow Hedging Relationships Location of Gain or Loss Recognized in Income on Derivatives Amount of (Loss) or Gain Recognized in AOCL on Derivatives Amount of (Loss) or Gain Reclassified from AOCL into Income Interest Expense on Condensed Consolidated Statements of Operations 2020 2019 2020 2019 2020 2019 Interest rate swaps Interest expense $ (6,795) $ (26,585) $ (9,805) $ 477 $ (40,022) $ (51,050)

Leases (Tables)

Leases (Tables)	6 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Schedules of Lease Cost	The Company’s total lease cost is recorded primarily within general and administrative expenses on the condensed consolidated statement of operations and consisted of the following: Three Months Ended Six Months Ended 2020 2019 2020 2019 Operating lease cost $ 17,214 $ 17,760 $ 34,341 $ 35,720 Short-term lease cost 1,426 2,333 3,027 4,750 Variable lease cost 3,281 3,016 6,815 5,578 Total operating lease costs $ 21,921 $ 23,109 $ 44,183 $ 46,048 Supplemental cash flow information related to leases was as follows: Six Months Ended 2020 2019 Cash paid for amounts included in the measurement of lease liabilities $ 35,594 $ 32,472 Operating lease liabilities arising from obtaining ROU assets (1) 28,292 9,681 (1) Includes all noncash increases and decreases arising from new or remeasured operating lease arrangements Other information related to leases was as follows: September 30, 2020 Weighted average remaining lease term (in years) 5.71 Weighted average discount rate 4.75 %
Schedule of Future Minimum Operating Lease Payments	Future minimum operating lease payments for noncancelable operating leases as of September 30, 2020 are as follows: Fiscal Year Ending Operating Lease Payments Remainder of 2021 $ 30,050 2022 70,358 2023 67,896 2024 56,728 2025 52,177 Thereafter 92,226 Total future lease payments 369,435 Less: imputed interest (50,211) Total lease liabilities $ 319,224

Other Long-Term Liabilities (Ta

Other Long-Term Liabilities (Tables)	6 Months Ended
	Sep. 30, 2020
Other Liabilities Disclosure [Abstract]
Summary of Other Long-Term Liabilities	Other long-term liabilities consisted of the following: September 30, March 31, Postretirement benefit obligations 126,502 124,375 Other (1) 202,873 207,312 Total other long-term liabilities $ 329,375 $ 331,687

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Components of net postretirement medical expense	The components of net postretirement medical expense for the Officer Medical Plan were as follows: Three Months Ended Six Months Ended 2020 2019 2020 2019 Service cost $ 1,414 $ 1,239 $ 2,828 $ 2,478 Interest cost 1,059 1,215 2,118 2,430 Total postretirement medical expense $ 2,473 $ 2,454 $ 4,946 $ 4,908

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of accumulated other comprehensive loss	The following table shows the changes in accumulated other comprehensive loss, net of tax: Three Months Ended September 30, 2020 Six Months Ended September 30, 2020 Post-retirement plans Derivatives designated as cash flow hedges Totals Post-retirement plans Derivatives designated as cash flow hedges Totals Beginning of period $ (4,105) $ (43,313) $ (47,418) $ (4,127) $ (41,874) $ (46,001) Other comprehensive loss before reclassifications (1) — (301) (301) — (5,023) (5,023) Amounts reclassified from accumulated other comprehensive loss 22 3,965 3,987 44 7,248 7,292 Net current-period other comprehensive income 22 3,664 3,686 44 2,225 2,269 End of period $ (4,083) $ (39,649) $ (43,732) $ (4,083) $ (39,649) $ (43,732) (1) Changes in other comprehensive income (loss) before reclassification for derivatives designated as cash flow hedges are recorded net of tax benefits of $0.1 million and $1.8 million for the three and six months ended September 30, 2020, respectively. Three Months Ended September 30, 2019 Six Months Ended September 30, 2019 Post-retirement plans Derivatives designated as cash flow hedges Totals Post-retirement plans Derivatives designated as cash flow hedges Totals Beginning of period $ (9,034) $ (17,087) $ (26,121) $ (9,068) $ (2,122) $ (11,190) Other comprehensive loss before reclassifications (2) — (5,048) (5,048) — (19,627) (19,627) Amounts reclassified from accumulated other comprehensive loss 16 34 50 50 (352) (302) Net current-period other comprehensive income (loss) 16 (5,014) (4,998) 50 (19,979) (19,929) End of period $ (9,018) $ (22,101) $ (31,119) $ (9,018) $ (22,101) $ (31,119) (2) Changes in other comprehensive loss before reclassification for derivatives designated as cash flow hedges are recorded net of tax benefits of $1.8 million and $7.0 million for the three and six months ended September 30, 2019, respectively.
Reclassification out of accumulated other comprehensive loss to net income	The following table presents the reclassifications out of accumulated other comprehensive loss to net income: Three Months Ended Six Months Ended 2020 2019 2020 2019 Amounts reclassified from accumulated other comprehensive loss: Post-retirement plans (Note 13): Amortization of net actuarial loss included in net periodic benefit cost $ 28 $ 22 $ 57 $ 66 Tax (benefit) expense (6) (6) (13) (16) Net of tax $ 22 $ 16 $ 44 $ 50 Derivatives designated as cash flow hedges (Note 9): Reclassification of hedge loss (gain) $ 5,364 $ 46 $ 9,805 $ (477) Tax (benefit) expense (1,399) (12) (2,557) 125 Net of tax $ 3,965 $ 34 $ 7,248 $ (352)

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Expense Recognized in the Condensed Consolidated Statements of Operations	The following table summarizes stock-based compensation expense recognized in the condensed consolidated statements of operations: Three Months Ended Six Months Ended 2020 2019 2020 2019 Cost of revenue $ 5,769 $ 2,538 $ 10,267 $ 4,472 General and administrative expenses 9,030 6,826 15,365 11,336 Total $ 14,799 $ 9,364 $ 25,632 $ 15,808 The following table summarizes the total stock-based compensation expense recognized in the condensed consolidated statements of operations by the following types of equity awards; Three Months Ended Six Months Ended 2020 2019 2020 2019 Equity Incentive Plan Options $ 684 $ 722 $ 1,130 $ 1,207 Restricted Stock Awards $ 14,115 8,642 24,502 14,601 Total $ 14,799 $ 9,364 $ 25,632 $ 15,808
Schedule of Unrecognized Compensation Cost	Absent the effect of accelerating stock compensation cost for any departures of employees who may continue to vest in their equity awards, the following table summarizes the unrecognized compensation cost and the weighted-average period the cost is expected to be amortized. September 30, 2020 Unrecognized Compensation Cost Weighted Average Remaining Period to be Recognized (in years) Equity Incentive Plan Options $ 4,972 3.79 Restricted Stock Awards 60,963 1.87 Total $ 65,935

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Recurring Fair Value Measurements	The financial instruments measured at fair value in the accompanying condensed consolidated balance sheets consist of the following: Recurring Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Long-term deferred compensation plan asset (1) 12,913 — — 12,913 Total Assets $ 12,913 $ — $ — $ 12,913 Liabilities: Contingent consideration liability (2) $ — $ — $ 1,223 1,223 Current derivative instruments (3) — 19,820 — 19,820 Long-term derivative instruments (3) — 33,819 — 33,819 Long-term deferred compensation plan liability (1) 12,913 — — 12,913 Total Liabilities $ 12,913 $ 53,639 $ 1,223 $ 67,775 Recurring Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Long-term deferred compensation plan asset (1) 5,879 — — 5,879 Total Assets $ 5,879 $ — $ — $ 5,879 Liabilities: Contingent consideration liability (2) $ — $ — $ 1,224 $ 1,224 Current derivative instruments (3) — 18,831 — 18,831 Long-term derivative instruments (3) — 37,819 — 37,819 Long-term deferred compensation plan liability (1) 5,879 — — 5,879 Total Liabilities $ 5,879 $ 56,650 $ 1,224 $ 63,753 (1) Investments in this category consist primarily of mutual funds whose fair values are determined by reference to the quoted market price per unit in active markets multiplied by the number of units held without consideration of transaction costs. These assets represent investments held in a consolidated trust to fund the Company's non-qualified deferred compensation plan and are recorded in other long-term assets and other long-term liabilities on our condensed consolidated balance sheets. (2) The Company recognized a contingent consideration liability of $3.6 million in connection with its acquisition of Aquilent in fiscal 2017. As of both September 30, 2020 and March 31, 2020, the estimated fair value of the contingent consideration liability was $1.2 million, and was valued using probability-weighted cash flows, which is based on the use of Level 3 fair value measurement inputs. (3) The Company’s interest rate swaps are considered over-the-counter derivatives and fair value is estimated based on the present value of future cash flows using a model-derived valuation that uses Level 2 observable inputs such as interest rate yield curves. See Note 9 to the condensed consolidated financial statements for further discussion on the Company’s derivative instruments designated as cash flow hedges.

Business Overview (Details)

Business Overview (Details)	6 Months Ended
	Sep. 30, 2020employeesegment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments	1
Number of reportable segments	1
Number of employees | employee	27,600

Revenue - Schedules of Disaggre

Revenue - Schedules of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 2,019,185	$ 1,819,577	$ 3,975,638	$ 3,644,753
Total revenue (as a percent)	100.00%	100.00%	100.00%	100.00%
Prime Contractor
Disaggregation of Revenue [Line Items]
Revenue	$ 1,880,778	$ 1,676,522	$ 3,684,382	$ 3,349,952
Total revenue (as a percent)	93.00%	92.00%	93.00%	92.00%
Sub-contractor
Disaggregation of Revenue [Line Items]
Revenue	$ 138,407	$ 143,055	$ 291,256	$ 294,801
Total revenue (as a percent)	7.00%	8.00%	7.00%	8.00%
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue	$ 1,966,663	$ 1,761,502	$ 3,863,026	$ 3,531,538
Total revenue (as a percent)	97.00%	97.00%	97.00%	97.00%
Defense Clients | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue	$ 1,000,340	$ 845,270	$ 1,931,676	$ 1,704,206
Total revenue (as a percent)	50.00%	47.00%	49.00%	47.00%
Intelligence Clients | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue	$ 396,110	$ 405,220	$ 803,214	$ 824,287
Total revenue (as a percent)	19.00%	22.00%	20.00%	22.00%
Civil Clients | UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue	$ 570,213	$ 511,012	$ 1,128,136	$ 1,003,045
Total revenue (as a percent)	28.00%	28.00%	28.00%	28.00%
Global Commercial Clients
Disaggregation of Revenue [Line Items]
Revenue	$ 52,522	$ 58,075	$ 112,612	$ 113,215
Total revenue (as a percent)	3.00%	3.00%	3.00%	3.00%
Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenue	$ 1,138,501	$ 1,026,055	$ 2,230,549	$ 2,052,648
Total revenue (as a percent)	56.00%	57.00%	56.00%	56.00%
Time-and-materials
Disaggregation of Revenue [Line Items]
Revenue	$ 504,663	$ 423,605	$ 1,007,209	$ 844,200
Total revenue (as a percent)	25.00%	23.00%	25.00%	23.00%
Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	$ 376,021	$ 369,917	$ 737,880	$ 747,905
Total revenue (as a percent)	19.00%	20.00%	19.00%	21.00%

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue, amount of remaining performance obligation	$ 8,400		$ 8,400		$ 6,300
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, amount of remaining performance obligation	8,400		8,400		$ 6,300
Contract with customer, liability, revenue recognized	$ 2.5	$ 1.7	$ 22	$ 18.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, expected timing, period one			12 months
Remaining performance obligation, expected timing, period two			24 months
Remaining performance obligation, percentage	75.00%		75.00%

Revenue - Schedule of Contract

Revenue - Schedule of Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Contract assets:
Current	$ 1,022,558	$ 988,634
Long-term	63,294	62,600
Total	1,085,852	1,051,234
Contract liabilities:
Advance payments, billings in excess of costs incurred and deferred revenue	$ 28,840	$ 26,018

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Earnings for basic computations	$ 135,283	$ 113,725	$ 263,951	$ 230,492
Earnings for diluted computations	$ 135,286	$ 113,728	$ 263,958	$ 230,499
Dilutive stock options and restricted stock (in shares)	864,734	1,117,098	987,262	1,127,138
Earnings per common share
Basic (in dollars per share)	$ 0.98	$ 0.81	$ 1.91	$ 1.64
Diluted (in dollars per share)	$ 0.98	$ 0.80	$ 1.90	$ 1.63
Unvested shares, cash dividends paid			$ 86,836	$ 64,848
Restricted stock
Earnings per common share
Unvested shares participating in the payment of the Company's dividends declared (in shares)	800,000	700,000	800,000	700,000
Unvested shares, cash dividends paid	$ 300	$ 200	$ 500	$ 300
Undistributed earnings allocated to participating securities, basic	500	400	1,000	900
Undistributed earnings allocated to participating securities, diluted	$ 500	$ 400	$ 1,000	$ 900
Stock options
Earnings per common share
Antidilutive options excluded from the computation of EPS (in shares)	300,000	200,000	200,000	200,000
Class A Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted-average common shares outstanding for basic computations (in shares)	137,882,906	140,245,038	138,017,120	140,125,779
Weighted-average common shares outstanding for diluted computations (in shares)	138,747,640	141,362,136	139,004,382	141,252,917

Accounts Receivable, Net of A_3

Accounts Receivable, Net of Allowance (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Current assets
Accounts receivable–billed	$ 449,382		$ 449,382		$ 474,822
Accounts receivable–unbilled	1,022,558		1,022,558		988,634
Allowance for doubtful accounts	(4,359)		(4,359)		(3,985)
Accounts receivable, net of allowance	1,467,581		1,467,581		1,459,471
Other long-term assets
Accounts receivable–unbilled	63,294		63,294		62,600
Total accounts receivable, net	1,530,875		1,530,875		$ 1,522,071
Provision (benefit) for doubtful accounts	$ (90)	$ 500	$ (120)	$ 2,400

Accounts Payable and Other Ac_3

Accounts Payable and Other Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Payables and Accruals [Abstract]
Vendor payables	$ 452,804	$ 432,953
Accrued expenses	400,081	265,058
Total accounts payable and other accrued expenses	852,885	698,011
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Provision for claimed indirect costs	$ 237,500	$ 224,600

Accrued Compensation and Bene_3

Accrued Compensation and Benefits (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Compensation Related Costs [Abstract]
Bonus	$ 45,024	$ 114,359
Retirement	75,548	41,604
Vacation	210,977	159,512
Other	28,998	33,300
Total accrued compensation and benefits	$ 360,547	$ 348,775

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020	Nov. 26, 2019	Nov. 25, 2019
Long-term Debt, Current and Noncurrent [Abstract]
Less: Unamortized debt issuance costs and discount on debt	$ (19,305)	$ (15,997)
Total	2,393,604	2,185,844
Less: Current portion of long-term debt	(77,865)	(177,865)
Long-term debt, net of current portion	2,315,739	$ 2,007,979
Revolver
Long-term Debt, Current and Noncurrent [Abstract]
Interest rate		3.75%
Long-term debt outstanding	$ 0	$ 100,000
Secured Debt | Term Loan A
Long-term Debt, Current and Noncurrent [Abstract]
Interest rate	1.65%	2.49%
Long-term debt outstanding	$ 1,326,752	$ 1,363,739
Secured Debt | Term Loan B
Long-term Debt, Current and Noncurrent [Abstract]
Interest rate	1.90%	2.74%
Long-term debt outstanding	$ 386,157	$ 388,102	$ 389,000	$ 389,000
Senior Notes | Senior Notes
Long-term Debt, Current and Noncurrent [Abstract]
Interest rate	3.88%	0.00%
Long-term debt outstanding	$ 700,000	$ 0
Senior Notes | 2017 Senior Notes
Long-term Debt, Current and Noncurrent [Abstract]
Interest rate	0.00%	5.13%
Long-term debt outstanding	$ 0	$ 350,000

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	Aug. 24, 2020	Nov. 26, 2019	Nov. 25, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020	Apr. 25, 2017
Debt Instrument [Line Items]
Long-term debt, maximum expanded loan facility						$ 627,000,000
Percentage of consolidated EBITDA required for expansion of loan						100.00%
Net secured leverage ratio						350.00%
Loss on debt extinguishment				$ 13,200,000		$ 13,239,000	$ 0
Payment of premium at redemption and write off of unamortized debt issuance costs				9,000,000
Term Loan B
Debt Instrument [Line Items]
Interest payments				1,900,000	$ 4,400,000	$ 4,100,000	8,800,000
Term Loan B | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate		1.75%	2.00%			1.75%
Term Loan B | Base Rate
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate		0.75%	1.00%			0.75%
Term Loan A
Debt Instrument [Line Items]
Interest payments				5,800,000	13,900,000	$ 12,700,000	27,200,000
Term Loan A | Minimum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						1.25%
Term Loan A | Maximum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						2.00%
Revolving Credit Facility
Debt Instrument [Line Items]
Revolving credit facility, maximum borrowing capacity				500,000,000		$ 500,000,000
Proceeds from lines of credit				0	$ 0	$ 0	$ 0
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						1.25%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						2.00%
Revolving Credit Facility | Base Rate | Minimum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						0.25%
Revolving Credit Facility | Base Rate | Maximum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						1.00%
Secured Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						1.00%
Secured Debt | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						0.00%
Secured Debt | Base Rate | Minimum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						0.00%
Secured Debt | Overnight Federal Funds Rate
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						0.50%
Secured Debt | Term Loan B
Debt Instrument [Line Items]
Long-term debt outstanding		$ 389,000,000	$ 389,000,000	$ 386,157,000		$ 386,157,000		$ 388,102,000
Premium payable (as a percent)		1.00%
Period for premium payable in connection with repricing transactions		6 months
Quarterly periodic payment percentage, principal				0.25%		0.25%
Secured Debt | Term Loan A
Debt Instrument [Line Items]
Long-term debt outstanding				$ 1,326,752,000		$ 1,326,752,000		1,363,739,000
Quarterly periodic payment percentage, principal				1.25%		1.25%
Secured Debt | Term Loan A | Base Rate | Minimum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						0.25%
Secured Debt | Term Loan A | Base Rate | Maximum
Debt Instrument [Line Items]
Long-term debt, basis spread on variable rate						1.00%
Secured Debt | Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Commitment fee percentage						0.20%
Secured Debt | Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Commitment fee percentage						0.35%
Revolving Credit Facility
Debt Instrument [Line Items]
Revolving credit facility, maximum borrowing capacity				$ 500,000,000		$ 500,000,000
Revolving credit facility, amount outstanding				0		0		100,000,000
Letter of Credit
Debt Instrument [Line Items]
Revolving credit facility, maximum borrowing capacity				100,000,000		100,000,000
Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt outstanding				700,000,000		700,000,000		0
Face amount of debt	$ 700,000,000
Debt instrument, stated percentage	3.875%
Redemption price (as a percent)	100.00%
Debt issuance costs	$ 9,200,000
Senior Notes | Senior Notes due 2025
Debt Instrument [Line Items]
Long-term debt outstanding				0		0		$ 350,000,000
Face amount of debt	$ 350,000,000								$ 350,000,000
Debt instrument, stated percentage									5.125%
Redemption price (as a percent)	102.563%
Designated as Hedging Instrument | Interest Rate Swap | Cash Flow Hedging
Debt Instrument [Line Items]
Notional amount of interest rate swaps				$ 1,000,000,000		$ 1,000,000,000
September 1, 2023 | Senior Notes | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)	101.94%
September 1, 2024 | Senior Notes | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)	100.97%
September 1, 2025 | Senior Notes | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)	100.00%
Prior to September 1, 2023 | Senior Notes | Senior Notes
Debt Instrument [Line Items]
Redemption price (as a percent)	103.88%
Redemption of aggregate principal amount (as a percent)	40.00%
Redemption of original principal amount, redemption period (in days)	180 days
Prior to September 1, 2023 | Senior Notes | Senior Notes | Minimum
Debt Instrument [Line Items]
Redemption of original principal amount (as a percent)	50.00%

Debt - Schedule of Interest Exp

Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Deferred payment on obligation interest	$ 0	$ 2,011	$ 0	$ 4,022
Amortization of Debt Issuance Cost (DIC) and Original Issue Discount (OID)	1,106	1,425	2,176	2,459
Interest Swap Expense	5,364	46	9,805	(477)
Other	196	267	505	391
Total Interest Expense	19,787	25,863	40,022	51,050
Secured Debt | Term Loan A
Debt Instrument [Line Items]
Interest expense on debt	5,722	13,584	12,640	27,034
Secured Debt | Term Loan B
Debt Instrument [Line Items]
Interest expense on debt	1,894	4,232	4,108	8,652
Revolving Credit Facility
Debt Instrument [Line Items]
Interest expense on debt	0	0	799	0
Senior Notes
Debt Instrument [Line Items]
Interest expense on debt	$ 5,505	$ 4,298	$ 9,989	$ 8,969

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - USD ($)	Sep. 30, 2020	Mar. 31, 2020
Derivative [Line Items]
Estimate of amount to be reclassified over the next 12 months	$ 20,000,000
Other Current Liabilities
Derivative [Line Items]
Fair value of derivative liabilities	19,800,000	$ 18,800,000
Other Noncurrent Liabilities
Derivative [Line Items]
Fair value of derivative liabilities	33,800,000	$ 37,800,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap
Derivative [Line Items]
Notional amount of interest rate swaps	$ 1,000,000,000

Derivatives - Schedule of Effec

Derivatives - Schedule of Effect of Derivatives on Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest Expense on Condensed Consolidated Statements of Operations	$ (19,787)	$ (25,863)	$ (40,022)	$ (51,050)
Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Recognized in AOCL on Derivatives	(408)	(6,837)	(6,795)	(26,585)
Amount of Gain or (Loss) Reclassified from AOCL into Income	$ (5,364)	$ (46)	$ (9,805)	$ 477

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 17,214	$ 17,760	$ 34,341	$ 35,720
Short-term lease cost	1,426	2,333	3,027	4,750
Variable lease cost	3,281	3,016	6,815	5,578
Total operating lease costs	$ 21,921	$ 23,109	$ 44,183	$ 46,048

Leases - Minimum Future Obligat

Leases - Minimum Future Obligations for Operating Leases (Details) $ in Thousands	Sep. 30, 2020USD ($)
Leases [Abstract]
Remainder of 2021	$ 30,050
2022	70,358
2023	67,896
2024	56,728
2025	52,177
Thereafter	92,226
Total future lease payments	369,435
Less: imputed interest	(50,211)
Total lease liabilities	$ 319,224

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow and Other Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 35,594	$ 32,472
Operating lease liabilities arising from obtaining ROU assets	$ 28,292	$ 9,681
Weighted average remaining lease term (in years)	5 years 8 months 15 days
Weighted average discount rate (as a percent)	4.75%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Operating Loss Carryforwards [Line Items]
Effective income tax rate	22.40%	22.80%	23.30%	23.80%
Federal statutory rate (as a percent)			21.00%
Income tax uncertainty	$ 65.9		$ 65.9		$ 56.1
Reserve for uncertain tax positions, research and development tax credits	54.1		54.1
Reserve for uncertain tax positions, acquisitions	$ 10.2		10.2
Tax Years 2013-2015
Operating Loss Carryforwards [Line Items]
Income tax assessments			11.7
Tax Years 2016-2021
Operating Loss Carryforwards [Line Items]
Income tax assessments			$ 32.5

Other Long-Term Liabilities (De

Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Other Liabilities Disclosure [Abstract]
Postretirement benefit obligations	$ 126,502	$ 124,375
Other	202,873	207,312
Total other long-term liabilities	$ 329,375	$ 331,687

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Retirement Benefits [Abstract]
Employer matching contribution, percent of match			6.00%
Employees’ capital accumulation plan, total expense recognized	$ 40,200,000	$ 36,200,000	$ 81,300,000	$ 73,100,000
Employees’ capital accumulation plan, company-paid contributions	24,600,000	22,100,000	47,800,000	42,000,000
Defined Benefit Plan Disclosure [Line Items]
Employees’ capital accumulation plan, total expense recognized	40,200,000	36,200,000	81,300,000	73,100,000
Employees’ capital accumulation plan, company-paid contributions	24,600,000	22,100,000	47,800,000	42,000,000
Long-term disability obligation	10,700,000		$ 10,700,000		$ 10,700,000
Maximum eligible deferral of compensation, percentage			100.00%
Deferred compensation plan, assets	12,900,000		$ 12,900,000		5,900,000
Deferred compensation plan, liabilities	12,900,000		12,900,000		5,900,000
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation arrangement with individual, annual cash award granted per year of service, amount			10,000
Officer Medical Plan | Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,414,000	1,239,000	2,828,000	2,478,000
Interest cost	1,059,000	1,215,000	2,118,000	2,430,000
Total postretirement medical expense	2,473,000	$ 2,454,000	4,946,000	$ 4,908,000
Defined benefit plan, unfunded status of plan	$ 122,300,000		$ 122,300,000		$ 119,600,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss - Schedule of Changes in AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	$ 882,467	$ 748,823	$ 856,356	$ 675,366
Other comprehensive income (loss) before reclassifications	(301)	(5,048)	(5,023)	(19,627)
Amounts reclassified from accumulated other comprehensive loss	3,987	50	7,292	(302)
Total other comprehensive income (loss), net of tax	3,686	(4,998)	2,269	(19,929)
End of period	971,957	840,183	971,957	840,183
Other comprehensive income (loss) before reclassifications, tax	100	1,800	1,800	7,000
Post-retirement plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(4,105)	(9,034)	(4,127)	(9,068)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive loss	22	16	44	50
Total other comprehensive income (loss), net of tax	22	16	44	50
End of period	(4,083)	(9,018)	(4,083)	(9,018)
Derivatives designated as cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(43,313)	(17,087)	(41,874)	(2,122)
Other comprehensive income (loss) before reclassifications	(301)	(5,048)	(5,023)	(19,627)
Amounts reclassified from accumulated other comprehensive loss	3,965	34	7,248	(352)
Total other comprehensive income (loss), net of tax	3,664	(5,014)	2,225	(19,979)
End of period	(39,649)	(22,101)	(39,649)	(22,101)
Totals
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(47,418)	(26,121)	(46,001)	(11,190)
End of period	$ (43,732)	$ (31,119)	$ (43,732)	$ (31,119)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss - Reclassifications out of Accumulated Other Comprehensive Loss to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Post-retirement Plans
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 28	$ 22	$ 57	$ 66
Tax (benefit) expense	(6)	(6)	(13)	(16)
Net income	22	16	44	50
Derivatives designated as cash flow hedges
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	5,364	46	9,805	(477)
Tax (benefit) expense	(1,399)	(12)	(2,557)	125
Net income	$ 3,965	$ 34	$ 7,248	$ (352)

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 14,799	$ 9,364	$ 25,632	$ 15,808
Stock options | EIP
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	684	722	1,130	1,207
Restricted stock | Annual Incentive Plan | Class A Common Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	14,115	8,642	24,502	14,601
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	5,769	2,538	10,267	4,472
General and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 9,030	$ 6,826	$ 15,365	$ 11,336

Stock-Based Compensation - Unre

Stock-Based Compensation - Unrecognized Compensation (Details) $ in Thousands	6 Months Ended
	Sep. 30, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock-based compensation agreements	$ 65,935
Unrecognized compensation cost, amortization period	4 years 6 months
EIP | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock-based compensation agreements	$ 4,972
Unrecognized compensation cost, amortization period	3 years 9 months 14 days
EIP | Restricted stock | Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock-based compensation agreements	$ 60,963
Annual Incentive Plan | Restricted stock | Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, amortization period	1 year 10 months 13 days

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Plans (Details) $ / shares in Units, $ in Millions	3 Months Ended	119 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock, total fair value | $	$ 13.8
Stock options | EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding (in shares)	1,617,665	1,617,665
Stock options outstanding, unvested (in shares)	746,866	746,866
Restricted stock units (RSUs) | EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)	159,939
Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock purchased by employees (in shares)	59,214	2,778,872
Class A Common Stock | Restricted stock units (RSUs) | EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted (in shares)	20,829
Minimum | EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price on grant date (in dollars per share) | $ / shares	$ 75.11	$ 75.11
Maximum | EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price on grant date (in dollars per share) | $ / shares	$ 87.38	$ 87.38

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020	Mar. 31, 2017
Assets:
Long term deferred compensation costs	$ 12,900	$ 5,900
Liabilities:
Long term deferred compensation plan liability	12,900	5,900
Fair Value, Measurements, Recurring
Assets:
Long term deferred compensation costs	12,913	5,879
Total Assets	12,913	5,879
Liabilities:
Contingent consideration, liability	1,223	1,224
Current derivative instruments	19,820	18,831
Long term derivative instruments	33,819	37,819
Long term deferred compensation plan liability	12,913	5,879
Total Liabilities	67,775	63,753
Fair Value, Measurements, Recurring | Level 1
Assets:
Long term deferred compensation costs	12,913	5,879
Total Assets	12,913	5,879
Liabilities:
Contingent consideration, liability	0	0
Current derivative instruments	0	0
Long term derivative instruments	0	0
Long term deferred compensation plan liability	12,913	5,879
Total Liabilities	12,913	5,879
Fair Value, Measurements, Recurring | Level 2
Assets:
Long term deferred compensation costs	0	0
Total Assets	0	0
Liabilities:
Contingent consideration, liability	0	0
Current derivative instruments	19,820	18,831
Long term derivative instruments	33,819	37,819
Long term deferred compensation plan liability	0	0
Total Liabilities	53,639	56,650
Fair Value, Measurements, Recurring | Level 3
Assets:
Long term deferred compensation costs	0	0
Total Assets	0	0
Liabilities:
Contingent consideration, liability	1,223	1,224
Current derivative instruments	0	0
Long term derivative instruments	0	0
Long term deferred compensation plan liability	0	0
Total Liabilities	1,223	1,224
Other noncurrent liabilities | Fair Value, Measurements, Recurring | Level 3
Liabilities:
Contingent consideration, liability	$ 1,200	$ 1,200	$ 3,600

Related-Party Transactions (Det

Related-Party Transactions (Details) - Affiliated Entity - Services Performed Under Subcontractor $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020USD ($)director	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)director	Sep. 30, 2019USD ($)
Related Party Transaction [Line Items]
Number of directors | director	2		2
Payments to related party | $	$ 21.7	$ 15.6	$ 45	$ 39.8

Commitments and Contingencies -

Commitments and Contingencies - Guarantees and Contracts (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Contracts with U.S. government agencies or other U.S. government contractors
Concentration Risk [Line Items]
Concentration risk, percentage	97.00%	97.00%	97.00%	97.00%
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Liability for reductions and/or penalties from U.S Government audits	$ 237.5		$ 237.5		$ 224.6
Financial Standby Letter of Credit
Concentration Risk [Line Items]
Guarantor obligations, carrying value	11.3		11.3		9.7
Guarantor obligations, reduction to available borrowings			0.9		0.9
Guarantor obligations, facility	20		20
Guarantor obligations, available amount	$ 9.6		$ 9.6		$ 6.2

Commitments and Contingencies_2

Commitments and Contingencies - Litigation (Details)	Sep. 05, 2017plaintiff
United States District Court for the Eastern District of Virginia styled Langley v. Booz Allen Hamilton Holding Corp.
Loss Contingencies [Line Items]
Loss contingencies, number of plaintiffs	2