LEASES - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Lessee Lease Description [Line Items]
Operating lease right-of-use assets	$ 10,307,000		$ 10,307,000		$ 9,421,000
Operating lease liabilities	$ 10,644,000		$ 10,644,000		$ 9,737,000
Weighted average discount rate	2.82%		2.82%		3.11%
Weighted average lease term	6 years 3 months 21 days		6 years 3 months 21 days		6 years 3 days
Operating lease costs	$ 697,000	$ 789,000	$ 2,100,000	$ 2,400,000
Variable lease costs	$ 75,000	$ 82,000	$ 242,000	$ 259,000
Minimum [Member]
Lessee Lease Description [Line Items]
Remaining lease term			2 months		1 month
Maximum [Member]
Lessee Lease Description [Line Items]
Remaining lease term			15 years		16 years