LEASES - Right-of-use lease assets and lease liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Right-of-use lease assets and lease liabilities
Operating right-of-use assets, net	$ 24,469	$ 8,358
Current portion of operating lease liabilities	5,674	1,959
Long-term operating lease liabilities	18,705	6,554
Total operating lease liabilities	24,379	8,513
Finance lease right-of-use assets, net	54	60
Current portion of finance lease liabilities	22	24
Long-term finance lease liabilities	35	39
Total finance lease liabilities	$ 57	$ 63