Income Taxes (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Income Tax [Abstract]
Deferred Tax Assets, Deferred Income	$ 4
Valuation Allowances and Reserves, Balance	$ (4)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
Effective Income Tax Rate as Result of Tax Reform Legislation	21.00%