Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Federal -
Current	$ 57	$ 42	$ 771
Deferred	1,035	898	40
Total federal taxes	1,092	940	811
State -
Current	8	(54)	100
Deferred	119	140	(15)
Total state taxes	127	86	85
Income taxes	$ 1,219	$ 1,026	$ 896