EQUITY SECURITIES - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Summary of Investment Holdings [Line Items]
Capital stock par value	$ 100		$ 100
Book value of investment in FHLB stock	$ 33,500		$ 33,500		$ 34,100
Market-to-market gains (losses)	10,132	$ 9,411	29,263	$ 28,277
Equity Securities [Member]
Summary of Investment Holdings [Line Items]
Equity Securities, FV-NI	1,500		1,500		1,400
Market-to-market gains (losses)		(2)	40	10
Equity Securities without Readily Determinable Fair Value, Amount	4,300		4,300		$ 2,800
Investment in Federal Home Loan Bank Stock [Member]
Summary of Investment Holdings [Line Items]
Dividend income from FHLB stock	$ 400	$ 700	$ 1,500	$ 2,000