Income Taxes (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Expense [Line Items]
Federal	$ 190	$ 27	$ (168)
State and other income tax	49	21	26
Total current income taxes	239	48	(142)
Federal	39	318	415
State and other income tax	8	(98)	42
Total deferred income taxes	47	220	457
Total	286	268	315
Discontinued operations	(29)	(1)	(4)
Total	$ 257	$ 267	$ 311