Financial Derivatives (Derivative Assets and Liabilities Offsetting) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	$ 3,838	$ 3,768
Derivative Asset, Fair Value Offset Amount	1,396	1,523
Derivative asset, cash collateral	1,593	714
Derivative Asset, Net	849	1,531
Derivative Asset, Securities Collateral Held Under Master Netting Agreements	118	34
Derivative Asset, Fair Value, Amount Offset Against Collateral	731	1,497
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	8,220	7,618
Derivative liability, fair value offset amount	1,396	1,523
Derivative liability, cash collateral	1,599	1,571
Derivative liability, net	5,225	4,524
Derivative liability, fair value of collateral	87	82
Derivative liability, fair value, amount offset against collateral	5,138	4,442
Interest Rate Contracts | Over-the-counter cleared
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	43	23
Derivative Asset, Net	43	23
Derivative Asset, Fair Value, Amount Offset Against Collateral	43	23
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	30	28
Derivative liability, net	30	28
Derivative liability, fair value, amount offset against collateral	30	28
Interest Rate Contracts | Over-the-counter
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	2,796	2,100
Derivative Asset, Fair Value Offset Amount	1,014	974
Derivative asset, cash collateral	1,318	630
Derivative Asset, Net	464	496
Derivative Asset, Securities Collateral Held Under Master Netting Agreements	116	34
Derivative Asset, Fair Value, Amount Offset Against Collateral	348	462
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	7,226	5,801
Derivative liability, fair value offset amount	811	625
Derivative liability, cash collateral	1,567	1,041
Derivative liability, net	4,848	4,135
Derivative liability, fair value of collateral	87	78
Derivative liability, fair value, amount offset against collateral	4,761	4,057
Commodity contracts:
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	548	1,208
Derivative Asset, Fair Value Offset Amount	250	335
Derivative asset, cash collateral	71	2
Derivative Asset, Net	227	871
Derivative Asset, Securities Collateral Held Under Master Netting Agreements	2
Derivative Asset, Fair Value, Amount Offset Against Collateral	225	871
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	577	1,269
Derivative liability, fair value offset amount	459	679
Derivative liability, cash collateral	31	520
Derivative liability, net	87	70
Derivative liability, fair value of collateral		4
Derivative liability, fair value, amount offset against collateral	87	66
Foreign exchange contracts and other
Offsetting Derivative Assets [Abstract]
Derivative asset, gross fair value	451	437
Derivative Asset, Fair Value Offset Amount	132	214
Derivative asset, cash collateral	204	82
Derivative Asset, Net	115	141
Derivative Asset, Fair Value, Amount Offset Against Collateral	115	141
Offsetting Derivative Liabilities [Abstract]
Derivative liability, gross fair value	387	520
Derivative liability, fair value offset amount	126	219
Derivative liability, cash collateral	1	10
Derivative liability, net	260	291
Derivative liability, fair value, amount offset against collateral	$ 260	$ 291