LEASES - Narrative (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)
Leases [Abstract]
Weighted average lease term for operating leases	7 years	7 years
Lease cost	$ 2,320	$ 4,806
Operating lease cost	1,903	3,886
Short-term and variable lease costs	417	920
Operating lease, right of use asset	29,715	29,715
Current portion of lease liability for operating leases	5,498	5,498
Long-term portion of lease liability for operating leases	$ 25,390	$ 25,390
Weighted average discount rate for operating leases	3.02%	3.02%