DERIVATIVES - Effect of Customer Derivatives and Economic Hedges on Net Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	$ (72)	$ 443	$ 263
Economic hedges | Foreign exchange and interest rate products | Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	(374)	1,234	687
Economic hedges | Foreign exchange and interest rate products | Derivatives hedging interest rate risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	401	(1,188)	(620)
Economic hedges | Foreign exchange and interest rate products | Customer foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	(207)	216	(166)
Economic hedges | Foreign exchange and interest rate products | Derivatives hedging foreign exchange risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	305	(263)	200
Economic hedges | Foreign exchange and interest rate products | Other derivative contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	779	(9)	0
Economic hedges | Foreign exchange and interest rate products | Derivatives hedging commodity price risk
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	(770)	13	0
Economic hedges | Mortgage banking fees | Residential loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	(208)	179	8
Economic hedges | Mortgage banking fees | 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	152	(50)	20
Economic hedges | Mortgage banking fees | Derivative contracts used to hedge residential MSRs(1)
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income	$ (150)	311	$ 134
Economic hedges | Mortgage banking fees | Interest rate derivative contracts used to hedge residential MSRs, at LOCOM
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income		$ (5)