LEASES - Reconciliation of future undiscounted cash flows to the operating and finance lease liabilities, and the related ROU assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Operating leases
2022 (excluding the six months ended March 31, 2022)	$ 2,843
2023	5,244
2024	4,198
2025	3,639
2026 and thereafter	20,161
Total minimum lease payments	36,085
Less: amounts representing interest	5,145
Present value of net minimum lease payments	30,940
Less: current portion of lease obligations	4,638
Non-current portion of lease obligations	26,302	$ 28,032
ROU assets	30,139	$ 31,846
Finance leases
2022 (excluding the six months ended March 31, 2022)	1,100
2023	2,256
2024	2,315
2025	2,370
2026 and thereafter	21,431
Total minimum lease payments	29,472
Less: amounts representing interest	7,670
Present value of net minimum lease payments	21,802
Less: current portion of lease obligations	1,277
Non-current portion of lease obligations	20,525
ROU assets	$ 18,129
Location of operating lease liabilities included on Consolidated Balance Sheets	Accrued other expenses, Other liabilities
Location of finance lease liabilities included on Consolidated Balance Sheets	Accrued other expenses, Other liabilities
Location of operating lease ROU assets included on Consolidated Balance Sheets	ROU assets
Location of finance lease ROU assets included on Consolidated Balance Sheets	Property, Plant and Equipment, Net