LEASES - Right-of-use lease assets and lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Right-of-use lease assets and lease liabilities
Operating ROU assets, net	$ 42,014	$ 32,489
Current portion of operating lease liabilities	10,061	7,982
Long-term operating lease liabilities	32,730	24,854
Total operating lease liabilities	42,791	32,836
Finance ROU assets, net	$ 65	$ 79
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets, Noncurrent	Other Assets, Noncurrent
Current portion of long-term finance lease	$ 39	$ 43
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities, Current	Accrued Liabilities, Current
Long-term finance lease liabilities	$ 34	$ 41
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Total finance lease liabilities	$ 73	$ 84