COMMITMENTS AND CONTINGENCIES - Narrative (Details)	3 Months Ended		6 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2017 USD ($) Letter_of_credit	Mar. 31, 2016 USD ($)	Apr. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Loss Contingencies [Line Items]
Rent expense	$ 930,000	$ 963,000	$ 1,925,000	$ 1,919,000
Sublease income	37,000	35,000	75,000	71,000
Pending Litigation | Professional Fees
Loss Contingencies [Line Items]
Legal fees	253,000	$ 228,000	799,000	$ 453,000
Pending Litigation | Accounts Payable and Other Liabilities
Loss Contingencies [Line Items]
Estimate of possible loss	1,131,000		$ 1,131,000			$ 832,000
Letter of Credit
Loss Contingencies [Line Items]
Number of letters of credit, outstanding | Letter_of_credit			3
Maximum borrowing capacity	$ 354,000		$ 354,000
Subsequent Event
Loss Contingencies [Line Items]
Security deposit					$ 1,151,000
First Four Years of Lease | Subsequent Event
Loss Contingencies [Line Items]
Monthly rent payment					64,000
Fifth Year of Lease | Subsequent Event
Loss Contingencies [Line Items]
Monthly rent payment					$ 67,000