DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Notional Amounts of All Derivative Instruments (Detail) - Not Designated as Hedging Instrument, Economic Hedge [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Economic undesignated hedges:
Notional amount of derivatives	$ 130,490	$ 94,894
Interest Rate Swap [Member]
Economic undesignated hedges:
Notional amount of derivatives	16,680	0
Sale of TBA GNMA MBS pools [Member]
Economic undesignated hedges:
Notional amount of derivatives	35,000	35,000
Forward loan sales commitments [Member]
Economic undesignated hedges:
Notional amount of derivatives	25,097	6,418
Interest Rate Lock Commitments [Member]
Economic undesignated hedges:
Notional amount of derivatives	24,713	11,456
Interest Rate Cap [Member] | Written
Economic undesignated hedges:
Notional amount of derivatives	14,500	21,010
Interest Rate Cap [Member] | Purchase
Economic undesignated hedges:
Notional amount of derivatives	$ 14,500	$ 21,010