Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Valuation allowance period increase (decrease)	$ 0
Deferred tax assets, period increase (decrease)	4
Operating loss carryforwards	289
Operating loss carryforward not subject to expiration	153
Unrecognized tax benefits	2	$ 2	$ 1
Unrecognized tax benefits that would impact effective tax rate	2
Deferred tax assets	11	30
Deferred tax liabilities	13	17
Deferred tax liabilities for unremitted foreign earnings	7
Estimated foreign earnings	146
Other Noncurrent Liabilities
Income Tax Contingency [Line Items]
Unrecognized tax benefits	1
Deferred tax liabilities	13	17
Other Current Liabilities
Income Tax Contingency [Line Items]
Unrecognized tax benefits	1
Investments And Other Non Current Assets
Income Tax Contingency [Line Items]
Deferred tax assets	11	$ 30
Research and Development Tax Credit Carryforward
Income Tax Contingency [Line Items]
Tax credit carryforwards	$ 2