Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Amortization Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 5	$ 6	$ 16	$ 18
Cost of service and other
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	2	0	6	0
Cost of product
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	3	1	3	3
Operating expenses
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	5	6	16	18
Total amortization
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 10	$ 7	$ 25	$ 21