LEASES - Additional information related to leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 1,375	$ 1,380	$ 2,800	$ 2,717
Operating cash flows from finance leases	311	198	623	335
Financing cash flows from finance leases	$ 419	$ 377	$ 838	$ 753
Weighted-average remaining lease term
Operating leases	5 years 9 months 3 days	6 years 4 months 13 days	5 years 9 months 3 days	6 years 4 months 13 days
Finance leases	12 years 2 months 12 days	12 years 8 months 12 days	12 years 2 months 12 days	12 years 8 months 12 days
Weighted-average discount rate
Operating leases	3.11%	3.08%	3.11%	3.08%
Finance leases	4.31%	4.28%	4.31%	4.28%