Income Taxes Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 10	$ 4	$ 20
State and local	3	1	2
Current Income Tax Expense (Benefit)	13	5	22
Deferred:
Federal	23	26	26
State and local	14	14	13
deferred income tax expense	37	40	39
Income tax expense	$ 50	$ 45	$ 61