Accounting for Derivative Instruments and Hedging Activities - Offsetting of Derivatives by Counterparty Master Agreement level and Collateral Received (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Offsetting of Derivatives by Counterparty Master Agreement Level and Collateral Received or Paid
Cash Collateral (Held)/Posted	$ (845)	$ (19)
Cash Collateral (Held)/Posted	291	50
Gross Amounts of Recognized Assets / Liabilities	2,341
Derivative Instruments	0
Cash Collateral (Held) / Posted	(814)
Net Amount	1,527
Foreign exchange contract
Offsetting of Derivatives by Counterparty Master Agreement Level and Collateral Received or Paid
Derivative Assets	1
Derivative Instruments	(1)
Cash Collateral (Held)/Posted	0
Net Amount	0
Derivative liabilities	(1)
Derivative Instruments	1
Cash Collateral (Held)/Posted	0
Net Amount	0
Gross Amounts of Recognized Assets / Liabilities	0
Derivative Instruments	0
Cash Collateral (Held) / Posted	0
Net Amount	0
Commodity contracts
Offsetting of Derivatives by Counterparty Master Agreement Level and Collateral Received or Paid
Derivative Assets	7,139	821
Derivative Instruments	(4,440)	(658)
Cash Collateral (Held)/Posted	(831)	(5)
Net Amount	1,868	158
Derivative liabilities	(4,798)	(884)
Derivative Instruments	4,440	658
Cash Collateral (Held)/Posted	17	0
Net Amount	(341)	(226)
Gross Amounts of Recognized Assets / Liabilities	2,341	(63)
Derivative Instruments	0	0
Cash Collateral (Held) / Posted	(814)	(5)
Net Amount	$ 1,527	$ (68)