Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Amortization Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 1	$ 3	$ 3	$ 4
Cost of service and other
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	8	8	16	16
Cost of product
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	4	3	9	7
Operating expenses
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	1	3	3	4
Total amortization
Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 13	$ 14	$ 28	$ 27