Derivative Instruments - Customer-Related Derivative Positions (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Notional Value	$ 1,200,000
Customer-Related Positions
Derivative [Line Items]
Notional Value	1,108,732	$ 1,119,842
Fair Value, Assets	5,854	6,219
Fair Value, Liabilities	8,679	8,068
Customer-Related Positions | Interest rate contracts | Receive fixed/pay floating swaps
Derivative [Line Items]
Notional Value	373,670	363,375
Fair Value, Assets	391	791
Fair Value, Liabilities	5,291	4,395
Customer-Related Positions | Interest rate contracts | Pay fixed/receive floating swaps
Derivative [Line Items]
Notional Value	338,302	330,539
Fair Value, Assets	2,182	1,817
Fair Value, Liabilities	183	280
Customer-Related Positions | Interest rate contracts | Other
Derivative [Line Items]
Notional Value	79,395	82,209
Fair Value, Assets	15	17
Fair Value, Liabilities	48	51
Customer-Related Positions | Interest rate contracts | Options | Buy/ Purchased
Derivative [Line Items]
Notional Value	94,801	102,423
Fair Value, Assets	889	1,026
Fair Value, Liabilities	2	18
Customer-Related Positions | Interest rate contracts | Options | Sell/ Written
Derivative [Line Items]
Notional Value	90,927	97,690
Fair Value, Assets	4	20
Fair Value, Liabilities	1,034	1,087
Customer-Related Positions | Foreign exchange rate contracts | Forwards, spots and swaps
Derivative [Line Items]
Notional Value	109,255	121,119
Fair Value, Assets	2,036	2,252
Fair Value, Liabilities	1,789	1,942
Customer-Related Positions | Foreign exchange options | Buy/ Purchased
Derivative [Line Items]
Notional Value	785	1,532
Fair Value, Assets	16	28
Fair Value, Liabilities	0	0
Customer-Related Positions | Foreign exchange options | Sell/ Written
Derivative [Line Items]
Notional Value	785	1,532
Fair Value, Assets	0	0
Fair Value, Liabilities	16	28
Customer-Related Positions | Commodity contracts | Swaps
Derivative [Line Items]
Notional Value	3,303	2,498
Fair Value, Assets	141	116
Fair Value, Liabilities	133	110
Customer-Related Positions | Commodity contracts | Futures | Sell/ Written
Derivative [Line Items]
Notional Value	5	0
Fair Value, Assets	1	0
Fair Value, Liabilities	1	0
Customer-Related Positions | Commodity options | Buy/ Purchased
Derivative [Line Items]
Notional Value	2,464	1,936
Fair Value, Assets	178	151
Fair Value, Liabilities	1	0
Customer-Related Positions | Commodity options | Sell/ Written
Derivative [Line Items]
Notional Value	2,464	1,936
Fair Value, Assets	1	0
Fair Value, Liabilities	177	151
Customer-Related Positions | Credit contracts
Derivative [Line Items]
Notional Value	12,576	13,053
Fair Value, Assets	0	1
Fair Value, Liabilities	$ 4	$ 6