Provision for Income Taxes (Schedule of Current and Deferred income Tax Expense) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Current U.S. federal tax expense (benefit)	$ 121	$ 353	$ (142)
Current U.S. state and local tax expense (benefit)	16	(20)	(9)
Current international tax expense (benefit)	663	482	401
Total current tax expense (benefit) on continuing operations	800	815	250
Deferred U.S. federal tax expense (benefit)	(103)	(147)	240
Deferred U.S. state and local tax expense (benefit)	(46)	(4)	22
Deferred international tax expense (benefit)	(29)	(38)	3
Total deferred tax (benefit) expense on continuing operations	(178)	(189)	265
Provision for income taxes on continuing operations	$ 622	$ 626	$ 515