Segment Information (Net Revenue By Timing Recognition) (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	$ 5,629	$ 5,537	$ 4,950
Recognized at a point in time
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	2,006	2,043	1,902
Recognized over time
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	$ 3,623	$ 3,494	$ 3,048