Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Amortization Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	$ 2	$ 4	$ 6	$ 11
Cost of service and other
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	9	8	25	27
Cost of product
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	3	4	10	11
Operating expenses
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	2	4	6	11
Total amortization
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	$ 14	$ 16	$ 41	$ 49