Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Amortization Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	$ 1	$ 3
Cost of service and other
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	8	10
Cost of product
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	4	4
Operating expenses
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	1	3
Total amortization
Finite-Lived Intangible Assets Classified by Expense
Amortization of intangibles	$ 13	$ 17