Financial and Derivative Instruments - Effect of Netting Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Not Designated
Offsetting Assets [Abstract]
Derivative Assets, Gross Amount Recognized	$ 1,761	$ 818
Derivative Assets, Gross Amounts Offset	1,639	744
Derivative Assets, Net Amounts Presented	122	74
Derivative Assets, Gross Amounts Not Offset	0	0
Derivative Assets, Net Amounts Presented	122	74
Offsetting Liabilities [Abstract]
Derivative Liabilities, Gross Amount Recognized	1,869	917
Derivative Liabilities, Gross Amounts Offset	1,639	744
Derivative Liabilities, Net Amounts Presented	230	173
Derivative Liabilities, Gross Amounts Not Offset	1	0
Derivative Liabilities, Net Amounts Presented	229	$ 173
Designated
Offsetting Liabilities [Abstract]
Derivative Liabilities, Gross Amount Recognized	2
Derivative Liabilities, Gross Amounts Offset	0
Derivative Liabilities, Net Amounts Presented	2
Derivative Liabilities, Gross Amounts Not Offset	0
Derivative Liabilities, Net Amounts Presented	$ 2