(Schedule Of Amortization Of Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 30	$ 22	$ 23
Cost of revenue [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	4	12	4
Operating expenses
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	30	22	23
Total amortization
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 34	$ 34	$ 27