Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Unrecognized Tax Benefit Rollforward [Abstract]
Unrecognized Tax Benefits, Beginning Balance	$ 157	$ 103
Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions	2	2
Unrecognized Tax Benefits Decreases Resulting From Current Period Tax Positions	0	(2)
Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions	69	53
Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions	(55)	(8)
Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities	(7)	(9)
Unrecognized Tax Benefits, Ending Balance	166	139
Unrecognized Tax Benefits That Would Impact Effective Tax Rate	117
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit	$ 16