LEASES - LEASE COST (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Operating lease cost	$ 1,356	$ 1,719	$ 3,445	$ 3,111
Amortization of right-of-use assets	1,191	1,299	2,437	2,460
Interest on lease liabilities	113	301	334	548
Total finance lease cost	1,304	1,600	2,771	3,008
Short-term lease cost	127	172	254	626
Variable lease cost	549	403	702	1,110
Total lease cost	$ 3,336	$ 3,894	$ 7,172	$ 7,855