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COMMITMENTS AND CONTINGENCIES - ADDITIONAL INFORMATION (Details) £ in Thousands, ft² in Thousands, € in Millions				12 Months Ended
	Jun. 11, 2018 USD ($)	Jun. 11, 2018 EUR (€)	May 03, 2018 USD ($)	Sep. 30, 2018 USD ($) ft²	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2018 EUR (€) ft²	Sep. 30, 2018 GBP (£) ft²
Loss Contingencies [Line Items]
Company contribution, percent of designated deferral of eligible compensation				25.00%
Company contribution, percent of employee compensation eligible for company match				6.00%
Employer contribution amount				$ 123,000	$ 121,000	$ 91,000
Annual base rent				1,000,000.0
Tenant improvement allowances				1,000,000.0
Unamortized lease incentives				800,000
Rent expense for the Company's operating leases				1,700,000	$ 600,000	$ 300,000
Line of Credit \| Revolving Credit Facility
Loss Contingencies [Line Items]
Maximum borrowing capacity			$ 10,000,000.0
Interest rate floor			0.045
Minimum unrestricted cash and unused borrowing capacity			$ 15,000,000.0
Adjusted quick ratio requirement			1.75
Borrowings outstanding				0
Line of Credit \| Revolving Credit Facility \| Prime Rate
Loss Contingencies [Line Items]
Basis spread on variable rate			0.25%
NETHERLANDS
Loss Contingencies [Line Items]
Annual base rent				200,000			€ 0.2
UNITED KINGDOM
Loss Contingencies [Line Items]
Annual base rent				82,000				£ 63
Other Current Liabilities
Loss Contingencies [Line Items]
Unamortized lease incentives				100,000
Other Noncurrent Liabilities
Loss Contingencies [Line Items]
Unamortized lease incentives				$ 700,000
Building
Loss Contingencies [Line Items]
Space area subject to lease (in square feet) \| ft²				29			29	29
ICAR \| SPAIN
Loss Contingencies [Line Items]
Annual base rent				$ 100,000			€ 0.1
A2iA \| FRANCE
Loss Contingencies [Line Items]
Annual base rent				400,000			€ 0.4
A2iA \| UNITED STATES
Loss Contingencies [Line Items]
Annual base rent				$ 300,000
Global Equity & Corporate Consulting, S.L.- Breach of Services Agreement \| Pending Litigation \| ICAR
Loss Contingencies [Line Items]
Loss contingency, amount claimed	$ 900,000	€ 0.8