Acquisitions - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019	May 31, 2018	Mar. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 2,671	$ 3,179		$ 2,022
Vencore
Business Acquisition [Line Items]
Current assets			$ 333
Property and equipment			35
Intangible assets			753
Other assets			40
Accounts payable, accrued payroll, accrued expenses, and other current liabilities			(194)
Deferred revenue			(12)
Deferred tax liabilities			(10)
Other liabilities			(119)
Net identifiable assets acquired			826
Goodwill			1,146
Total estimated consideration transferred			$ 1,972