Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 2,251		$ 2,251		$ 2,310
Intangible Assets Gross Excluding Goodwill	18,599		18,599		18,276
Amortization of Intangible Assets	176	96	351	195
Finite-Lived Intangible Assets [Line Items]
Gross Amount	16,348		16,348		15,966
Accumulated Amortization	(3,298)		(3,298)		(3,087)
Service Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,181		2,181		2,127
Accumulated Amortization	(1,216)		(1,216)		(1,202)
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	378		378		412
Accumulated Amortization	(171)		(171)		(167)
Collaboration [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	1,845		1,845		1,526
Accumulated Amortization	0		0		0
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	11,944		11,944		11,901
Accumulated Amortization	$ (1,911)		$ (1,911)		$ (1,718)