Acquisitions - Luxoft, Purchase Price Allocation (Details) - USD ($) $ in Millions	Mar. 31, 2020	Jun. 14, 2019	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 2,017		$ 7,606	$ 7,619
Luxoft
Business Acquisition [Line Items]
Cash and cash equivalents		$ 113
Accounts receivable		233
Other current assets		15
Total current assets		361
Property and equipment		31
Intangible assets		577
Other assets		99
Total assets acquired		1,068
Accounts payable, accrued payroll, accrued expenses, and other current liabilities		(121)
Deferred revenue		(8)
Long-term deferred tax liabilities and income tax payable		(106)
Other liabilities		(72)
Total liabilities assumed		(307)
Net identifiable assets acquired		761
Goodwill		1,262
Total consideration transferred		$ 2,023