Goodwill And Acquisition-Related Intangibles, Net (Schedule Of Amortization Of Intangible Assets) (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2013
Finite-Lived Intangible Assets Classified by Expense      
Amortization of intangibles $ 14 $ 16 $ 30
Cost of product      
Finite-Lived Intangible Assets Classified by Expense      
Amortization of intangibles 16 33 55
Cost of service and other      
Finite-Lived Intangible Assets Classified by Expense      
Amortization of intangibles 36 27 38
Operating expenses      
Finite-Lived Intangible Assets Classified by Expense      
Amortization of intangibles 14 16 30
Total amortization      
Finite-Lived Intangible Assets Classified by Expense      
Amortization of intangibles $ 66 $ 76 $ 123