Income Taxes (Components of Income Tax Provision) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Abstract]
Current income taxes, Federal	$ 123	$ 134	$ 130
Current income taxes, State	36	21	37
Current income taxes, Foreign	28	33	16
Total current income taxes	187	188	183
Deferred income taxes, Federal	(13)	13	(10)
Deferred income taxes, State	(2)	11	6
Deferred income taxes, Foreign	9	4	20
Total deferred income taxes	(6)	28	16
Total income tax provision	$ 181	$ 216	$ 199