Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax Benefit, Federal Law Changes	$ 110	$ 0	$ 0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	17	17
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, Beginning balance	18	17	13
Unrecognized tax benefits, increase from prior years positions netted against DTA	(1)	(2)	5
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions		3	1
Gross increases - tax positions during 2012	2	2	0
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(1)
Gross decreases - lapse of statue of limitations	0	(2)	(2)
Gross decreases - settlements with taxing authorities	0	0	0
Unrecognized tax benefits, Ending Balance	18	18	17
Accrued interest and penalties in the Company's liability for uncertain tax positions	(18)	(16)	(17)
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 1
Accrued interest and penalties related to uncertain tax positions in income tax expense in its consolidated statements of operation		$ (1)	$ (1)