Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets, carryforwards
Tax credit carry forwards	$ 33,000,000
Uncertain tax liability	77,000,000
AMT tax credit carryforward	17,000,000
State tax credits	13,000,000
AMT Tax Credit Carryforward	13,000,000
Deferred Tax Assets, Release Of Valuation Allowance	5,000,000
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	22,000,000
Unrecognized tax positions that would affect the effective tax rate	99,000,000	$ 98,000,000	$ 33,000,000
Income Tax Examination, Interest Accrued	3,000,000
Income Tax Examination, Penalties Accrued	3,000,000
Domestic Tax Authority
Deferred tax assets, carryforwards
Tax credit carry forwards	458,000,000
Operating loss carry forward	60,000,000
Operating Loss Carryforwards	4
State and Local Jurisdiction
Deferred tax assets, carryforwards
Operating loss carry forward	4,000,000
Operating Loss Carryforwards	$ 50