Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$ 0	$ 4	$ (33)	$ 28
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 25	48	$ 25
Minimum
Income Tax Contingency [Line Items]
Reasonable possible decrease in unrecognized tax benefits	25		25
Maximum
Income Tax Contingency [Line Items]
Reasonable possible decrease in unrecognized tax benefits	$ 32		32
Out of period adjustments - stock compensation permanent differences [Member]
Income Tax Contingency [Line Items]
Income tax expense (benefit)			2
Out of period adjustments - write-off of income tax payables [Member]
Income Tax Contingency [Line Items]
Income tax expense (benefit)			$ 3