Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits, Beginning Balance	$ 22	[1]	$ 89	[1]	$ 66
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	31		1		0
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	2		1		29
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	(2)		(65)		(1)
Unrecognized Tax Benefits, Ending Balance	44	[1]	22	[1]	89	[1]
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	$ (9)		$ (4)		$ (5)

[1] Unrecognized tax benefits on our Consolidated Balance Sheets as of December 31, 2012, 2011 and 2010, include tax benefits of $12 million, $5 million and $72 million, respectively, which will affect the effective tax rate when recognized.