DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Derivative [Line Items]
Notional amount	$ 14,098,000,000		$ 14,526,000,000
Additional amount in excess of posted collateral required in case of breached agreements	100,000		200,000
Subject to Master Netting Arrangement
Derivative [Line Items]
Notional amount	$ 7,449,000,000		7,627,000,000
Interest rate contracts
Derivative [Line Items]
Maximum length of time hedged in interest rate cash flow hedge	3 years 6 months
Period to reclassification of cash flow hedge gain loss	12 months
Derivative gains to be reclassified within twelve months	$ 11,200,000
Derivative gains to be reclassified within twelve months, net of tax	8,700,000
Derivative gain or losses excluded from assessment of hedge effectiveness	0
Amount of gain (loss) reclassified from AOCI into net income	0	$ 0
Interest rate contracts | Subject to Master Netting Arrangement
Derivative [Line Items]
Notional amount	1,980,000,000		2,080,000,000
Credit risk contracts
Derivative [Line Items]
Notional amount	249,800,000
Maximum exposure under credit risk agreement assuming customer default	100,000		200,000
Credit risk derivatives, purchased at fair value	100,000		100,000
Credit risk derivatives, sold at fair value	$ 100,000		$ 200,000
Credit risk contracts | Minimum
Derivative [Line Items]
Risk participation agreements, term	4 months
Credit risk contracts | Maximum
Derivative [Line Items]
Risk participation agreements, term	19 years