Income Taxes - Tax Contingencies (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Income Tax Contingency [Line Items]
Liabilities associated with uncertain tax positions	$ 186	$ 182
Unrecognized tax benefits, income tax penalties and interest accrued	13	12
Noncurrent Deferred Tax Assets
Income Tax Contingency [Line Items]
Liabilities associated with uncertain tax positions	2	2
Other Taxes Payable
Income Tax Contingency [Line Items]
Liabilities associated with uncertain tax positions	$ 184	$ 180