DERIVATIVES - Effect of Customer Derivatives and Economic Hedges on Net Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	$ (49)	$ 12	$ (52)	$ 22
Economic hedges | Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	70	(189)	235	(683)
Economic hedges | Derivatives hedging interest rate risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(62)	197	(219)	700
Economic hedges | Customer foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	319	(23)	417	(133)
Economic hedges | Derivatives hedging foreign exchange risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(399)	37	(530)	182
Economic hedges | Customer commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	(302)	32	41	67
Economic hedges | Derivatives hedging commodity price risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	307	(25)	(29)	(57)
Economic hedges | Residential loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	3	(5)	9	(7)
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	(1)	6	(14)	9
Economic hedges | Derivative contracts used to hedge residential MSRs
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	5	(18)	27	(56)
Economic hedges | Derivative contracts used to hedge equity price risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts recognized in noninterest income	$ 11	$ 0	$ 11	$ 0