Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019	Apr. 01, 2017
Income Tax Disclosure [Abstract]
Domestic entities	$ 975	$ (2,928)	$ 511
Entities outside the United States	(321)	(2,300)	1,004
Income (loss) from continuing operations, before taxes	654	(5,228)	1,515
Income Tax Contingency [Line Items]
Transition tax included in current provision (benefit)	(4)	(31)	(44)
Interest and penalties for uncertain tax positions included in current expenses	$ 2	$ 2	1
Hewlett Packard Enterprise Services
Income Tax Contingency [Line Items]
Tax indemnification receivable related to net uncertain tax positions				$ 34
Tax indemnification receivable related to other tax payables				70
Tax indemnification payable related to other tax receivables				$ 118
Discontinued Operations | USPS Separation
Income Tax Contingency [Line Items]
Tax indemnification receivable related to disposal			72
Tax indemnification payable related to disposal			$ 33