Goodwill, Capitalized Software and Other Intangible Assets 3 (Details) $ in Millions	3 Months Ended
	Jun. 30, 2017 USD ($)
Goodwill activity by segment
Balance at March 31, 2017	$ 6,857
Acquisitions	(15)	[1]
Foreign currency translation adjustment	22
Balance at June 30, 2017	6,864
Mainframe Solutions
Goodwill activity by segment
Balance at March 31, 2017	4,178
Acquisitions	0
Foreign currency translation adjustment	0
Balance at June 30, 2017	4,178
Enterprise Solutions
Goodwill activity by segment
Balance at March 31, 2017	2,598
Acquisitions	(15)	[1]
Foreign currency translation adjustment	22
Balance at June 30, 2017	2,605
Services
Goodwill activity by segment
Balance at March 31, 2017	81
Acquisitions	0
Foreign currency translation adjustment	0
Balance at June 30, 2017	$ 81

[1] Acquisitions amount relates to purchase price allocation adjustments that occurred during the three months ended June 30, 2017.