Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Net income tax payments/(refunds)				$ 355	$ 209	$ 410
Effective income tax rate				23.70%	26.40%	34.00%
Tax Adjustments, Settlements, and Unusual Provisions	188	212	145
U.S. deferred income taxes and foreign withholding tax	37			37
Undistributed Earnings of Foreign Subsidiaries	800			800
Accrued income tax-related interest	17	12		17	12
Accrued income tax-related penalties	5	8		5	8
Amounts of interest (benefit)/expense				(17)	(4)	(43)
Unrecognized tax benefits	1,312	1,141		1,312	1,141	1,055	939
Unrecognized tax benefits that would affect the effective tax rate, if recognized	$ 1,180	$ 1,018		$ 1,180	$ 1,018	$ 945