Intangible Assets Including Goodwill (Details 4) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2016	Dec. 31, 2015
Intangible Assets Including Goodwill:
Goodwill accumulated impairment losses	$ 0	$ 0
Goodwill impairment losses	0	0
Changes in Goodwill Balances
Beginning Balance	32,021	30,556
Goodwill Additions	1,915	2,590
Purchase Price Adjustments	4	(3)
Divestitures	(17)	(26)
Foreign Currency Translation and Other Adjustments	398	(1,096)
Ending Balance	34,322	32,021
Cognitive Solutions
Changes in Goodwill Balances
Beginning Balance	15,621	15,156
Goodwill Additions	1,723	1,020
Purchase Price Adjustments	1	(2)
Divestitures	(12)	(18)
Foreign Currency Translation and Other Adjustments	199	(535)
Ending Balance	17,533	15,621
Global Business Services
Changes in Goodwill Balances
Beginning Balance	4,396	4,555
Goodwill Additions	101	74
Purchase Price Adjustments	1	0
Divestitures	(1)	(1)
Foreign Currency Translation and Other Adjustments	72	(232)
Ending Balance	4,569	4,396
Technology Services & Cloud Platforms
Changes in Goodwill Balances
Beginning Balance	10,156	9,373
Goodwill Additions	91	1,087
Purchase Price Adjustments	1	(1)
Divestitures	(5)	(7)
Foreign Currency Translation and Other Adjustments	115	(296)
Ending Balance	10,358	10,156
Systems
Changes in Goodwill Balances
Beginning Balance	1,848	1,472
Goodwill Additions		410
Purchase Price Adjustments	1	0
Foreign Currency Translation and Other Adjustments	12	(33)
Ending Balance	$ 1,861	$ 1,848

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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