(Schedule Of Stock Option Activity) (Details) (USD $)
In Millions, except Share data in Thousands, unless otherwise specified
 12 Months Ended
Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]  
Options, Outstanding, Beginning Balance 5,311
Options, Granted 1,248
Options, Exercised (1,021)
Options, forfeited, cancelled or expired (618)
Options, Outstanding, Ending Balance 4,920
Options, vested and expected to vest 4,612
Options, Exercisable 3,006
Weighted-average exercise price of options outstanding, beginning balance $ 37.43
Weighted-average exercise price of options granted during period $ 35.79
Weighted-Average Exercise Prices, Exercised during period $ 23.76
Weighted-Average Exercise Prices, Forfeited, cancelled or expired during period $ 56.66
Weighted-average exercise price of options outstanding, ending balance $ 37.44
Weighted-average exercise price of options vested and expected to vest $ 37.82
Weighted-average exercise prices of options exercisable $ 40.90
Weighted-average remaining contractual term of options outstanding 5 years 4 months 29 days
Weighted-average remaining contractual term of options vested and expected to vest 5 years 1 month 30 days
Weighted-average remaining contractual term of options exercisable 3 years 1 month 20 days
Aggregate intrinsic value of options outstanding $ 102
Aggregate intrinsic value of options vested and expected to vest 94
Aggregate intrinsic value of options exercisable $ 52