Derivative Instruments - Customer-Related Derivative Positions (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Notional Value	$ 1,400,000
Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	103,569	$ 105,692
Fair Value, Assets	319	275
Fair Value, Liabilities	258	221
Customer-Related Positions
Derivative [Line Items]
Notional Value	1,308,688	1,181,606
Fair Value, Assets	6,653	6,162
Fair Value, Liabilities	6,711	7,939
Customer-Related Positions | Interest rate contracts | Receive fixed/pay floating swaps
Derivative [Line Items]
Notional Value	444,332	413,841
Fair Value, Assets	1,357	462
Fair Value, Liabilities	2,190	4,485
Customer-Related Positions | Interest rate contracts | Pay fixed/receive floating swaps
Derivative [Line Items]
Notional Value	382,650	363,837
Fair Value, Assets	1,124	2,342
Fair Value, Liabilities	481	153
Customer-Related Positions | Interest rate contracts | Other
Derivative [Line Items]
Notional Value	69,002	72,503
Fair Value, Assets	21	17
Fair Value, Liabilities	62	34
Customer-Related Positions | Interest rate contracts | Options | Buy/ Purchased
Derivative [Line Items]
Notional Value	134,864	96,238
Fair Value, Assets	254	414
Fair Value, Liabilities	9	2
Customer-Related Positions | Interest rate contracts | Options | Sell/ Written
Derivative [Line Items]
Notional Value	95,541	90,572
Fair Value, Assets	26	12
Fair Value, Liabilities	334	574
Customer-Related Positions | Interest rate contracts | Futures | Buy/ Purchased
Derivative [Line Items]
Notional Value	1,881	0
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Customer-Related Positions | Interest rate contracts | Futures | Sell/ Written
Derivative [Line Items]
Notional Value	963	0
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Customer-Related Positions | Foreign exchange rate contracts | Forwards, spots and swaps
Derivative [Line Items]
Notional Value	136,823	113,718
Fair Value, Assets	2,831	2,441
Fair Value, Liabilities	2,691	2,232
Customer-Related Positions | Foreign exchange options | Buy/ Purchased
Derivative [Line Items]
Notional Value	1,330	497
Fair Value, Assets	23	14
Fair Value, Liabilities	1	0
Customer-Related Positions | Foreign exchange options | Sell/ Written
Derivative [Line Items]
Notional Value	1,330	497
Fair Value, Assets	3	0
Fair Value, Liabilities	24	14
Customer-Related Positions | Commodity contracts | Swaps
Derivative [Line Items]
Notional Value	14,804	8,224
Fair Value, Assets	579	199
Fair Value, Liabilities	485	180
Customer-Related Positions | Commodity contracts | Futures | Buy/ Purchased
Derivative [Line Items]
Notional Value	4	1
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Customer-Related Positions | Commodity contracts | Futures | Sell/ Written
Derivative [Line Items]
Notional Value	548	166
Fair Value, Assets	84	25
Fair Value, Liabilities	81	27
Customer-Related Positions | Commodity options | Buy/ Purchased
Derivative [Line Items]
Notional Value	5,300	3,921
Fair Value, Assets	348	233
Fair Value, Liabilities	2	2
Customer-Related Positions | Commodity options | Sell/ Written
Derivative [Line Items]
Notional Value	5,293	3,921
Fair Value, Assets	2	3
Fair Value, Liabilities	348	233
Customer-Related Positions | Credit contracts
Derivative [Line Items]
Notional Value	14,015	13,670
Fair Value, Assets	1	0
Fair Value, Liabilities	3	3
Other economic hedges | Interest rate contracts | Receive fixed/pay floating swaps | Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	9,396	9,977
Fair Value, Assets	109	45
Fair Value, Liabilities	30	23
Other economic hedges | Interest rate contracts | Pay fixed/receive floating swaps | Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	2,983	2,371
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Other economic hedges | Interest rate contracts | Options | Buy/ Purchased | Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	9,520	7,810
Fair Value, Assets	145	186
Fair Value, Liabilities	0	0
Other economic hedges | Interest rate contracts | Options | Sell/ Written | Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	3,181	1,991
Fair Value, Assets	21	8
Fair Value, Liabilities	66	47
Other economic hedges | Credit contracts | Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	2,816	3,558
Fair Value, Assets	0	0
Fair Value, Liabilities	18	29
Other economic hedges | Equity contracts
Derivative [Line Items]
Notional Value	8	0
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Other economic hedges | Equity contracts | Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	321	293
Fair Value, Assets	8	0
Fair Value, Liabilities	$ 1	$ 9