LEASES - Additional information related to leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 1,320	$ 1,452	$ 4,102	$ 4,334
Operating cash flows from finance leases	306	319	915	655
Financing cash flows from finance leases	428	418	1,261	1,145
Right-of-use assets obtained in exchange for operating lease liabilities	$ 12,780	$ 53	$ 12,780	$ 22,072
Weighted-average remaining lease term
Operating leases	10 years 3 months 21 days	6 years 7 months 20 days	10 years 3 months 21 days	6 years 7 months 20 days
Finance leases	11 years 10 months 9 days	12 years 9 months 3 days	11 years 10 months 9 days	12 years 9 months 3 days
Weighted-average discount rate
Operating leases	3.12%	3.14%	3.12%	3.14%
Finance leases	4.31%	4.29%	4.31%	4.29%