Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Beginning Balance	$ 89	[1]	$ 66	[1]	$ 29
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	1		0		1
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	(3)		(3)		(1)
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	1		29		40
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	(1)		(2)
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	(65)		(1)		(3)
Unrecognized Tax Benefits, Ending Balance	$ 22	[1]	$ 89	[1]	$ 66	[1]

[1] Unrecognized tax benefits on our Consolidated Balance Sheets as of December 31, 2011, 2010 and 2009, include tax benefits of $5 million, $72 million, and $47 million, respectively, which will affect the effective tax rate when recognized.