Income Taxes (Details 2) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Reserves not yet deducted for tax purposes	$ 26	$ 23
State income taxes	5	9
Foreign exchange loss	7	0
Other	0	1
Gross deferred tax assets	38	33
Deferred tax liabilities:
Investment in foreign subsidiaries	105	0
Foreign exchange gain	0	8
Gross deferred tax liabilities	105	8
Net deferred tax assets	$ (67)	$ 25