Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 18,924	$ 18,104
Accumulated Amortization	5,192	4,570
Unamortized: Trademarks and Other	2,068	2,069
Total Intangible Assets Gross Excluding Goodwill	20,992	20,173
Service portfolios [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,068	1,977
Accumulated Amortization	1,404	1,307
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	379	361
Accumulated Amortization	202	189
IAE collaboration [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	3,637	3,336
Accumulated Amortization	176	86
Customer relationships and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	12,840	12,430
Accumulated Amortization	$ 3,410	$ 2,988