Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 19,944	$ 18,895
Accumulated Amortization	6,100	5,236
Unamortized: Trademarks and Other	2,111	2,025
Total Intangible Assets Gross Excluding Goodwill	22,055	20,920
Service portfolios [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,197	1,995
Accumulated Amortization	1,531	1,344
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	401	378
Accumulated Amortization	228	201
Collaboration intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	4,023	3,724
Accumulated Amortization	342	211
Customer relationships and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	13,323	12,798
Accumulated Amortization	$ 3,999	$ 3,480