Goodwill, Capitalized Software and Other Intangible Assets 3 (Details) $ in Millions	3 Months Ended
	Jun. 30, 2016 USD ($)
Goodwill activity by segment
Balance at March 31, 2016	$ 6,086
Foreign currency translation adjustment	(2)
Balance at June 30, 2016	6,084
Mainframe Solutions
Goodwill activity by segment
Balance at March 31, 2016	4,178
Foreign currency translation adjustment	0
Balance at June 30, 2016	4,178
Enterprise Solutions
Goodwill activity by segment
Balance at March 31, 2016	1,827
Foreign currency translation adjustment	(2)
Balance at June 30, 2016	1,825
Services
Goodwill activity by segment
Balance at March 31, 2016	81
Foreign currency translation adjustment	0
Balance at June 30, 2016	$ 81