REVENUE FROM CONTRACTS WITH CUSTOMERS - Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Contract assets
Trade receivables	$ 65,127	$ 88,867
Unbilled revenue	16,410	17,474
Contract liabilities
Customer deposits	36,761	39,222
Deferred revenue	18,435	29,420
Uncollectible invoices written off	$ 15,419	$ 2,647
Percentage of revenue billed from unbilled revenue	85.00%
Percentage of contract liabilities recognized as revenue	55.00%