Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 17,557		$ 17,557		$ 16,936
Accumulated Amortization	(4,097)		(4,097)		(3,675)
Unamortized: Trademarks and Other	2,224		2,224		2,260
Total Intangible Assets Gross Excluding Goodwill	19,781		19,781		19,196
Amortization of Intangible Assets	182	180	540	531
Service portfolios [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,183		2,183		2,234
Accumulated Amortization	(1,334)		(1,334)		(1,295)
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	376		376		380
Accumulated Amortization	(192)		(192)		(181)
IAE collaboration [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,738		2,738		2,273
Accumulated Amortization	(15)		(15)		0
Customer relationships and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	12,260		12,260		12,049
Accumulated Amortization	$ (2,556)		$ (2,556)		$ (2,199)