Derivative Instruments - Customer-Related Derivative Positions (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Derivative [Line Items]
Notional Value	$ 1,600,000
Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	101,194	$ 90,935
Fair Value, Assets	187	180
Fair Value, Liabilities	238	222
Customer-Related Positions
Derivative [Line Items]
Notional Value	1,528,359	1,353,721
Fair Value, Assets	6,913	6,672
Fair Value, Liabilities	7,396	6,570
Customer-Related Positions \| Interest rate contracts \| Receive fixed/pay floating swaps
Derivative [Line Items]
Notional Value	516,942	459,357
Fair Value, Assets	576	1,326
Fair Value, Liabilities	2,778	2,134
Customer-Related Positions \| Interest rate contracts \| Pay fixed/receive floating swaps
Derivative [Line Items]
Notional Value	430,898	386,099
Fair Value, Assets	1,668	1,142
Fair Value, Liabilities	211	449
Customer-Related Positions \| Interest rate contracts \| Other
Derivative [Line Items]
Notional Value	63,026	66,014
Fair Value, Assets	17	19
Fair Value, Liabilities	42	33
Customer-Related Positions \| Interest rate contracts \| Options \| Buy/ Purchased
Derivative [Line Items]
Notional Value	182,448	148,778
Fair Value, Assets	258	222
Fair Value, Liabilities	1	8
Customer-Related Positions \| Interest rate contracts \| Options \| Sell/ Written
Derivative [Line Items]
Notional Value	120,918	106,749
Fair Value, Assets	11	24
Fair Value, Liabilities	404	291
Customer-Related Positions \| Interest rate contracts \| Futures \| Buy/ Purchased
Derivative [Line Items]
Notional Value	17,207	3,974
Fair Value, Assets	0	0
Fair Value, Liabilities	10	0
Customer-Related Positions \| Interest rate contracts \| Futures \| Sell/ Written
Derivative [Line Items]
Notional Value	14	527
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	137,299	137,555
Fair Value, Assets	2,473	2,688
Fair Value, Liabilities	2,367	2,575
Customer-Related Positions \| Foreign exchange options \| Buy/ Purchased
Derivative [Line Items]
Notional Value	1,493	1,101
Fair Value, Assets	18	20
Fair Value, Liabilities	0	2
Customer-Related Positions \| Foreign exchange options \| Sell/ Written
Derivative [Line Items]
Notional Value	1,493	1,101
Fair Value, Assets	0	4
Fair Value, Liabilities	18	19
Customer-Related Positions \| Commodity contracts \| Swaps
Derivative [Line Items]
Notional Value	28,995	18,068
Fair Value, Assets	1,263	810
Fair Value, Liabilities	1,128	705
Customer-Related Positions \| Commodity contracts \| Futures \| Buy/ Purchased
Derivative [Line Items]
Notional Value	2	0
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Customer-Related Positions \| Commodity contracts \| Futures \| Sell/ Written
Derivative [Line Items]
Notional Value	1,139	631
Fair Value, Assets	302	138
Fair Value, Liabilities	105	71
Customer-Related Positions \| Commodity options \| Buy/ Purchased
Derivative [Line Items]
Notional Value	4,959	4,545
Fair Value, Assets	316	278
Fair Value, Liabilities	5	2
Customer-Related Positions \| Commodity options \| Sell/ Written
Derivative [Line Items]
Notional Value	4,949	4,539
Fair Value, Assets	11	1
Fair Value, Liabilities	313	278
Customer-Related Positions \| Credit contracts
Derivative [Line Items]
Notional Value	16,577	14,683
Fair Value, Assets	0	0
Fair Value, Liabilities	14	3
Other economic hedges \| Interest rate contracts \| Receive fixed/pay floating swaps \| Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	5,354	5,318
Fair Value, Assets	0	14
Fair Value, Liabilities	76	30
Other economic hedges \| Interest rate contracts \| Pay fixed/receive floating swaps \| Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	2,662	2,479
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	8,955	8,930
Fair Value, Assets	127	131
Fair Value, Liabilities	0	0
Other economic hedges \| Interest rate contracts \| Options \| Sell/ Written \| Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	2,922	2,553
Fair Value, Assets	16	13
Fair Value, Liabilities	49	58
Other economic hedges \| Credit contracts \| Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	2,509	2,265
Fair Value, Assets	0	0
Fair Value, Liabilities	10	18
Other economic hedges \| Equity contracts \| Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	366	334
Fair Value, Assets	5	2
Fair Value, Liabilities	$ 3	$ 1