DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Effect of Derivative Financial Instruments on Income Statement (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest rate swaps | Non-interest income - other
Derivative [Line Items]
Derivative financial instrument, net	$ 0	$ 0
Interest rate lock commitments | Mortgage banking operations
Derivative [Line Items]
Derivative financial instrument, net	0	0
Forward delivery contracts | Mortgage banking operations
Derivative [Line Items]
Derivative financial instrument, net	9	9
Credit risk contracts | Non-interest income - other
Derivative [Line Items]
Derivative financial instrument, net	$ 0	$ 0