Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 17,947		$ 17,947		$ 17,525
Accumulated Amortization	4,371		4,371		4,142
Unamortized: Trademarks and Other	2,130		2,130		2,177
Total Intangible Assets Gross Excluding Goodwill	20,077		20,077		19,702
Amortization of Intangible Assets	179	$ 178	358	$ 357
Service portfolios [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,006		2,006		2,103
Accumulated Amortization	1,295		1,295		1,309
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	389		389		361
Accumulated Amortization	196		196		190
IAE collaboration [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	3,118		3,118		2,872
Accumulated Amortization	45		45		20
Customer relationships and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	12,434		12,434		12,189
Accumulated Amortization	$ 2,835		$ 2,835		$ 2,623