Fair Value Measurements - Assets and Liabilities at Fair Value, Recurring (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Not Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	$ 494	$ 74
Derivatives - not designated	281	173
Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	4
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Total Assets at Fair Value	16
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	34	31
Total Assets at Fair Value	528	105
Total Liabilities at Fair Value	285	173
Recurring Basis | Not Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	494	74
Derivatives - not designated	281	173
Recurring Basis | Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	4	0
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	34	31
Total Assets at Fair Value	528	68
Total Liabilities at Fair Value	148	58
Recurring Basis | Level 1 | Not Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	494	37
Derivatives - not designated	144	58
Recurring Basis | Level 1 | Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	4	0
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	0	0
Total Assets at Fair Value	0	37
Total Liabilities at Fair Value	137	115
Recurring Basis | Level 2 | Not Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	0	37
Derivatives - not designated	137	115
Recurring Basis | Level 2 | Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	0	0
Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	0	0
Total Assets at Fair Value	0	0
Total Liabilities at Fair Value	0	0
Recurring Basis | Level 3 | Not Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	0	0
Derivatives - not designated	0	0
Recurring Basis | Level 3 | Designated
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives - not designated	$ 0	$ 0