Acquisitions - Summary of HPES Purchase Price (Details) - USD ($) $ in Millions		12 Months Ended
	May 31, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Goodwill		$ 2,671	$ 3,179	$ 2,022
Goodwill acquired during period		116	1,157
Hewlett Packard Enterprise Services
Business Acquisition [Line Items]
Cash and cash equivalents				0
Accounts receivable				403
Prepaid expenses				86
Other current assets				22
Total current assets				511
Property and equipment				183
Intangible assets				976
Other assets				28
Total assets acquired				1,698
Current finance lease obligations, accounts payable, accrued payroll, accrued expenses, and other current liabilities				418
Deferred revenue				71
Non-current finance lease obligations				162
Deferred tax liabilities				204
Other liabilities				15
Total liabilities assumed				870
Net identifiable assets acquired				828
Goodwill				2,022
Total estimated consideration transferred				2,850
Defense and Intelligence
Business Acquisition [Line Items]
Goodwill		1,449	2,051	977
Goodwill acquired during period	$ 1,070	22	1,074
Defense and Intelligence | Hewlett Packard Enterprise Services
Business Acquisition [Line Items]
Goodwill acquired during period				977
Civilian and Health Care
Business Acquisition [Line Items]
Goodwill		1,222	1,128	1,045
Goodwill acquired during period	$ 77	$ 94	$ 83
Civilian and Health Care | Hewlett Packard Enterprise Services
Business Acquisition [Line Items]
Goodwill acquired during period				$ 1,050