Income Taxes Schedule of Components of Income Tax Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current:
Federal	$ 2	$ (20)	$ (46)
State and local	0	0	0
Current Income Tax Expense (Benefit)	2	(20)	(46)
Deferred:
Federal	43	61	78
State and local	13	12	6
deferred income tax expense	56	73	84
Investment tax credit adjustments	0	0	(2)
Income tax expense	$ 58	$ 53	$ 36