Goodwill (Details) - USD ($) $ in Millions		12 Months Ended
May 31, 2018	Mar. 31, 2020	Mar. 31, 2019
Changes in the carrying amount of goodwill by segment [Roll Forward]
Goodwill, net, beginning of period		$ 3,179	$ 2,022
Additions		116	1,157
Impairment charges		(624)
Goodwill, net, end of period		2,671	3,179
Defense and Intelligence
Changes in the carrying amount of goodwill by segment [Roll Forward]
Goodwill, net, beginning of period		2,051	977
Additions	$ 1,070	22	1,074
Impairment charges		(624)
Goodwill, net, end of period		1,449	2,051
Civilian and Health Care
Changes in the carrying amount of goodwill by segment [Roll Forward]
Goodwill, net, beginning of period		1,128	1,045
Additions	$ 77	94	83
Impairment charges		0
Goodwill, net, end of period		$ 1,222	$ 1,128

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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