LEASES - Right-of-use lease assets and lease liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Right-of-use lease assets and lease liabilities
Operating ROU assets, net	$ 46,358	$ 49,165
Current portion of operating lease liabilities	6,896	11,774
Long-term operating lease liabilities	44,344	40,010
Total operating lease liabilities	51,240	51,784
Finance ROU assets, net	$ 2,900	$ 652
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities, Current	Accrued Liabilities, Current
Current portion of long-term finance lease	$ 495	$ 211
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other long-term liabilities	Other long-term liabilities
Long-term finance leases	$ 2,430	$ 433
Total finance lease liabilities	$ 2,925	$ 644