SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounts Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Opening balance	$ 1,759	$ 1,948
Charged to expense	180	0
Uncollectible invoices written off	(1,378)	(49)
Amounts collected	0	(140)
Ending balance	$ 561	$ 1,759