Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal	$ 0	$ (10)	$ (10)
State	20	18	14
Foreign	(3)	(14)	1
Total current	17	(6)	5
Federal	(1)	5	10
State	(6)	6	27
Foreign	54	3	6
Total deferred	47	14	43
Total income tax expense (benefit)	$ 64	$ 8	$ 48