Goodwill, Capitalized Software and Other Intangible Assets 3 (Details) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Dec. 31, 2014
Goodwill activity by segment  
Balance at March 31, 2014 $ 5,922
Divestiture (109)
Foreign currency translation adjustment (4)
Balance at December 31, 2014 5,809
Mainframe Solutions [Member]  
Goodwill activity by segment  
Balance at March 31, 2014 4,178
Divestiture 0
Foreign currency translation adjustment 0
Balance at December 31, 2014 4,178
Enterprise Solutions [Member]  
Goodwill activity by segment  
Balance at March 31, 2014 1,663
Divestiture (109)
Foreign currency translation adjustment (4)
Balance at December 31, 2014 1,550
Services [Member]  
Goodwill activity by segment  
Balance at March 31, 2014 81
Divestiture 0
Foreign currency translation adjustment 0
Balance at December 31, 2014 $ 81