Financial and Derivative Instruments - Effect of Netting Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Offsetting Assets [Abstract]
Derivative Assets, Gross Amount Recognized	$ 1,044	$ 656
Derivative Assets, Gross Amounts Offset	940	645
Derivative Assets, Net Amounts Presented	104	11
Derivative Assets, Gross Amounts Not Offset	0	0
Derivative Assets, Net Amounts Presented	104	11
Offsetting Liabilities [Abstract]
Derivative Liabilities, Gross Amount Recognized	948	719
Derivative Liabilities, Gross Amounts Offset	940	645
Derivative Liabilities, Net Amounts Presented	8	74
Derivative Liabilities, Gross Amounts Not Offset	0	0
Derivative Liabilities, Net Amounts Presented	$ 8	$ 74