Receivables - Schedule of Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019
Revenue from External Customer [Line Items]
Billed trade receivables	$ 173	$ 183
Unbilled receivables	341	301
Receivables, gross	514	484
Allowance for doubtful accounts	(1)	0
Receivables, net	513	484
U.S. federal government, including independent agencies
Revenue from External Customer [Line Items]
Receivables, net	468	430
Non-federal (state, local and other)
Revenue from External Customer [Line Items]
Receivables, net	$ 45	$ 54

Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Amount of allowance for credit loss on accounts receivable.

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Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

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