SUBORDINATED DEBT - Additional Information (Details) - Subordinated Debt [Member] - USD ($)	1 Months Ended			3 Months Ended
	Dec. 31, 2020	Dec. 31, 2017	Jun. 30, 2016	Jun. 30, 2021
Debt Instrument [Line Items]
Principal amount	$ 100,000,000.0	$ 35,000,000.0	$ 50,000,000.0
Non-callable term	5 years	5 years	5 years
Notes maturity date	Dec. 22, 2030	Dec. 15, 2027	Jun. 30, 2026
Fixed interest rate	3.50%	4.75%	6.00%
LIBOR spread	326.00%	2.54%	4.85%
Redemption of debt				$ 50,000,000.0
Debt costs net, written-off				$ 648,000
Debt issuance costs	$ 1,900,000	$ 875,000
Parent Company [Member]
Debt Instrument [Line Items]
Net proceeds used to contribute to the Bank		29,100,000
Proceeds from debt retained by parent		$ 5,000,000