Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Net income tax payments/(refunds)				$ 209	$ 410	$ 57
Effective income tax rate				26.40%	34.00%	25.60%
Income tax charge (benefit) recorded	(212)	(145)	(397)
U.S. deferred income taxes and foreign withholding tax	44			44
Undistributed Earnings of Foreign Subsidiaries	775			775
Accrued income tax-related interest	12			12	11
Accrued income tax-related penalties	8			8	11
Amounts of interest (benefit)/expense				(4)	(43)	(94)
Unrecognized tax benefits	1,141		939	1,141	1,055	939	1,198
Unrecognized tax benefits that would affect the effective tax rate, if recognized	1,018		838	1,018	945	838
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 245			$ 245