Financial Derivatives (Derivative Assets and Liabilities Offsetting) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	$ 5,935	$ 5,152
Derivative Asset, Fair Value Offset Amount	1,439	928
Derivative asset, cash collateral	491	604
Derivative Asset, Net	4,005	3,620
Derivative Asset, Securities Collateral Held Under Master Netting Agreements	77	300
Derivative Asset, Fair Value, Amount Offset Against Collateral	3,928	3,320
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	6,963	3,570
Derivative liability, fair value offset amount	1,439	928
Derivative liability, cash collateral	2,611	1,657
Derivative liability, net	2,913	985
Derivative liability, fair value of collateral
Derivative liability, fair value, amount offset against collateral	2,913	985
Interest Rate Contracts | Over-the-counter cleared
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	150	20
Derivative Asset, Net	150	20
Derivative Asset, Fair Value, Amount Offset Against Collateral	150	20
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	224	12
Derivative liability, net	224	12
Derivative liability, fair value, amount offset against collateral	224	12
Interest Rate Contracts | Over-the-counter
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	2,059	3,561
Derivative Asset, Fair Value Offset Amount	670	533
Derivative asset, cash collateral	277	593
Derivative Asset, Net	1,112	2,435
Derivative Asset, Securities Collateral Held Under Master Netting Agreements	77	300
Derivative Asset, Fair Value, Amount Offset Against Collateral	1,035	2,135
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	2,798	1,643
Derivative liability, fair value offset amount	672	569
Derivative liability, cash collateral	649	776
Derivative liability, net	1,477	298
Derivative liability, fair value, amount offset against collateral	1,477	298
Commodity contracts:
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	3,446	1,363
Derivative Asset, Fair Value Offset Amount	622	299
Derivative asset, cash collateral	183	1
Derivative Asset, Net	2,641	1,063
Derivative Asset, Fair Value, Amount Offset Against Collateral	2,641	1,063
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	3,448	1,373
Derivative liability, fair value offset amount	688	291
Derivative liability, cash collateral	1,917	784
Derivative liability, net	843	298
Derivative liability, fair value, amount offset against collateral	843	298
Foreign exchange contracts and other
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	280	208
Derivative Asset, Fair Value Offset Amount	147	96
Derivative asset, cash collateral	31	10
Derivative Asset, Net	102	102
Derivative Asset, Fair Value, Amount Offset Against Collateral	102	102
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	493	542
Derivative liability, fair value offset amount	79	68
Derivative liability, cash collateral	45	97
Derivative liability, net	369	377
Derivative liability, fair value, amount offset against collateral	$ 369	$ 377