Income Taxes Changes in Unrecognized Tax Benefits (Details) (Federal and State [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Federal and State [Member]
Changes in Unrecognized Tax Benefits [Line Items]
Unrecognized Tax Benefits	$ 210	$ 291	$ 137
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	1	4
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	(36)	(10)
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	87	171
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	(130)	(2)
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	$ (3)	$ (9)