Goodwill And Acquisition-Related Intangibles (Schedule Of Changes In The Carrying Amount Of Goodwill) (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Goodwill [Roll Forward]    
Goodwill, Gross, Beginning balance $ 2,091 $ 2,089
Accumulated impairment, beginning balance (368) (368)
Goodwill, Net, Beginning balance 1,723 1,721
Goodwill acquired 0 5
Effects of foreign currency translation (10) (3)
Goodwill, Gross, Ending balance 2,081 2,091
Accumulated impairment, ending balance (368) (368)
Goodwill, Net, Ending balance $ 1,713 $ 1,723