DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Cumulative Basis Adjustment for Fair Value Hedges (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
AFS debt securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amortized Cost	$ 0	$ 10,000
Cumulative Amount of Fair Value Hedging Adjustment to Hedged Items	0	0
Deposits
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amortized Cost	1,697,282	1,794,923
Cumulative Amount of Fair Value Hedging Adjustment to Hedged Items	22,495	(6,042)
FHLB advances
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amortized Cost	750,000	1,200,000
Cumulative Amount of Fair Value Hedging Adjustment to Hedged Items	$ 5,437	$ (1,648)