Financial Derivatives (Total Derivatives) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Derivative [Line Items]
Derivative, notional amount	$ 712,653	$ 701,952
Derivative asset, fair value	3,074	3,011
Derivative liability, fair value	4,730	5,495
Derivative asset, fair value offset amount	1,458	1,298
Derivative liability, fair value offset amount	1,458	1,298
Less: Cash collateral received/paid, derivative asset fair value	504	897
Less: Cash collateral received/paid, derivative liability fair value	897	1,029
Derivative assets, Net Fair Value	1,112	816
Derivative liabilities, Net Fair Value	2,375	3,168
Commodity contracts:
Derivative [Line Items]
Derivative asset, fair value	786	521
Derivative liability, fair value	762	496
Less: Cash collateral received/paid, derivative asset fair value	21	85
Less: Cash collateral received/paid, derivative liability fair value	53	2
Derivative assets, Net Fair Value	433	140
Derivative liabilities, Net Fair Value	203	101
Foreign exchange contracts and other
Derivative [Line Items]
Derivative asset, fair value	341	561
Derivative liability, fair value	480	513
Less: Cash collateral received/paid, derivative asset fair value	44	183
Less: Cash collateral received/paid, derivative liability fair value	13	8
Derivative assets, Net Fair Value	161	219
Derivative liabilities, Net Fair Value	284	332
Designated as Hedging Instruments under GAAP
Derivative [Line Items]
Derivative, notional amount	140,530	130,740
Derivative asset, fair value	196	163
Derivative liability, fair value	132	170
Designated as Hedging Instruments under GAAP | Fair value hedges | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	55,702	53,750
Derivative asset, fair value	0	0
Derivative liability, fair value	0	0
Designated as Hedging Instruments under GAAP | Cash flow hedges | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	58,578	50,721
Derivative asset, fair value	0	0
Derivative liability, fair value	0	2
Designated as Hedging Instruments under GAAP | Cash flow hedges | Other | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	25,000	25,000
Derivative asset, fair value	196	149
Derivative liability, fair value	105	168
Designated as Hedging Instruments under GAAP | Net investment hedges | Foreign Exchange Contract
Derivative [Line Items]
Derivative, notional amount	1,250	1,269
Derivative asset, fair value	0	14
Derivative liability, fair value	27	0
Not Designated as Hedging Instrument under GAAP
Derivative [Line Items]
Derivative, notional amount	572,123	571,212
Derivative asset, fair value	2,878	2,848
Derivative liability, fair value	4,598	5,325
Not Designated as Hedging Instrument under GAAP | Mortgage Banking | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	68,629	63,816
Derivative asset, fair value	122	92
Derivative liability, fair value	87	79
Not Designated as Hedging Instrument under GAAP | Mortgage Banking | Swaps | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	34,354	35,941
Derivative asset, fair value	0	0
Derivative liability, fair value	0	0
Not Designated as Hedging Instrument under GAAP | Mortgage Banking | Futures | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	6,967	9,962
Derivative asset, fair value	0	0
Derivative liability, fair value	0	0
Not Designated as Hedging Instrument under GAAP | Mortgage Banking | Mortgage-backed commitments | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	5,786	4,815
Derivative asset, fair value	75	73
Derivative liability, fair value	67	66
Not Designated as Hedging Instrument under GAAP | Mortgage Banking | Other | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	21,522	13,098
Derivative asset, fair value	47	19
Derivative liability, fair value	20	13
Not Designated as Hedging Instrument under GAAP | Customer Contracts
Derivative [Line Items]
Derivative, notional amount	489,712	496,365
Derivative asset, fair value	2,700	2,612
Derivative liability, fair value	4,294	5,097
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	436,676	442,415
Derivative asset, fair value	1,629	1,688
Derivative liability, fair value	3,296	4,237
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Commodity contracts:
Derivative [Line Items]
Derivative, notional amount	15,351	15,221
Derivative asset, fair value	786	521
Derivative liability, fair value	762	496
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Foreign exchange contracts and other
Derivative [Line Items]
Derivative, notional amount	37,685	38,729
Derivative asset, fair value	285	403
Derivative liability, fair value	236	364
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Swaps | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	399,382	406,747
Derivative asset, fair value	1,513	1,544
Derivative liability, fair value	3,200	4,130
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Swaps | Commodity contracts:
Derivative [Line Items]
Derivative, notional amount	6,351	6,725
Derivative asset, fair value	525	313
Derivative liability, fair value	502	288
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Futures | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	115	113
Derivative asset, fair value	0	0
Derivative liability, fair value	0	0
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Mortgage-backed commitments | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	5,165	3,275
Derivative asset, fair value	18	21
Derivative liability, fair value	18	7
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Other | Interest rate contracts
Derivative [Line Items]
Derivative, notional amount	32,014	32,280
Derivative asset, fair value	98	123
Derivative liability, fair value	78	100
Not Designated as Hedging Instrument under GAAP | Customer Contracts | Other | Commodity contracts:
Derivative [Line Items]
Derivative, notional amount	9,000	8,496
Derivative asset, fair value	261	208
Derivative liability, fair value	260	208
Not Designated as Hedging Instrument under GAAP | Other Risk Management Activity | Foreign exchange contracts and other
Derivative [Line Items]
Derivative, notional amount	13,782	11,031
Derivative asset, fair value	56	144
Derivative liability, fair value	$ 217	$ 149