Location of Gain (Loss) Recognized in Income on Derivative, Non-Designated Hedging Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Net revenue	$ 5,629	$ 5,537	$ 4,950
Research and development	1,778	1,559	1,433
Other Nonoperating Income (Expense)	(29)	63	83
Interest And Other Income (Expense), Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(19)	(4)	25
Sales Revenue, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(30)	71	18
Research and Development
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	$ 4	$ (9)	$ (10)