Income Taxes (Schedule of Unrecognized Tax Benefits Rollforward) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Balance at January 1	$ (972)	$ (857)	$ (199)
(Additions) reductions based on tax positions related to current year	(22)	12	(2)
Additions for tax positions of prior years	(29)	(140)	(719)
Reductions for tax positions of prior years	824	6	29
Settlements	26	2	2
Expiration of statutes of limitations	11	7	25
Currency translation adjustment	1	(2)	7
Balance at December 31	$ (161)	$ (972)	$ (857)