Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Income tax expense	$ 32	$ 1	$ 42
Income tax expense (benefit), domestic losses	23	(10)
Operating loss carryforwards	1,174
Operating loss carryforward not subject to expiration	1,085
Deferred tax assets	6	7
Deferred tax liabilities	12	13
Unrecognized tax benefits	7	4	$ 2
Unrecognized tax benefits that would impact effective tax rate	2
Deferred tax liabilities for unremitted foreign earnings	2
Estimated foreign earnings	32
Other Noncurrent Liabilities
Income Tax Contingency [Line Items]
Deferred tax liabilities	12	13
Investments And Other Non Current Assets
Income Tax Contingency [Line Items]
Deferred tax assets	6	$ 7
Research and Development Tax Credit Carryforward
Income Tax Contingency [Line Items]
Tax credit carryforwards	$ 14