Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Income Taxes [Abstract]
Net income tax payments/(refunds)				$ 57	$ 360	$ (198)
Effective income tax rate				25.60%	26.50%	22.90%
Income tax charge (benefit) recorded	(397)	(371)	150
U.S. federal statutory tax				35.00%	35.00%	35.00%
Net deferred tax assets related to Accumulated other comprehensive loss	9,743	8,186		9,743	8,186
U.S. deferred income taxes and foreign withholding tax				66
Accrued income tax-related interest	48	170		48	170
Accrued income tax-related penalties	10	12		10	12
Amounts of interest (benefit)/expense				(94)	(105)	45
Unrecognized tax benefits	939	1,198		939	1,198	1,787	1,453
Unrecognized tax benefits that would affect the effective tax rate, if recognized	$ 838	$ 1,074		$ 838	$ 1,074	$ 1,452
Research and development credits				2.70%	3.50%	10.10%