ADVANCES FROM THE FEDERAL HOME LOAN BANK (FHLB) - Summary of Advances from FHLB (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances [Line Items]
Fixed-rate advances from FHLB	$ 440,000	$ 570,000
Short-term Debt [Member]
Federal Home Loan Bank, Advances [Line Items]
Fixed-rate advances from FHLB	0	35,000
Long-term Debt [Member]
Federal Home Loan Bank, Advances [Line Items]
Fixed-rate advances from FHLB	$ 440,000	$ 535,000