DERIVATIVES - Effect of Customer Derivatives and Economic Hedges on Net Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	$ 43	$ 0	$ (9)	$ 22
Economic hedges | Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(17)	474	218	(209)
Economic hedges | Derivatives hedging interest rate risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	29	(467)	(190)	233
Economic hedges | Customer foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(72)	151	345	18
Economic hedges | Derivatives hedging foreign exchange risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	107	(195)	(423)	(13)
Economic hedges | Customer commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(122)	(193)	(81)	(126)
Economic hedges | Derivatives hedging commodity price risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	125	198	96	141
Economic hedges | Residential loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	4	9	13	2
Economic hedges | Derivatives hedging residential loan commitments and mortgage loans held for sale, at fair value
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(14)	(24)	(28)	(15)
Economic hedges | Derivative contracts used to hedge residential MSRs
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(1)	47	26	(9)
Economic hedges | Derivative contracts used to hedge equity price risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	$ 4	$ 0	$ 15	$ 0