Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Effective tax rate (as a percent)	0.00%	0.90%	14.20%	2.50%
Valuation allowance	$ 11		$ 11
Gross unrecognized tax benefits	38		38		$ 39
Unrecognized tax benefits, net of federal tax benefits, that would affect the effective tax rate if recognized	20		20		17
Interest and penalties recognized in income tax provision	0	$ 0	0	$ 0
Payable related to accrued interest and penalties	2		2		$ 2
State and local jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Deferred tax assets, loss carryforwards	$ 13		$ 13