Commitments and Contingencies - Additional Information (Details) £ in Thousands, ft² in Thousands, € in Millions								12 Months Ended
	Nov. 06, 2019 USD ($) patent	Jul. 31, 2019 claim customer	Aug. 17, 2018 patent	Jul. 07, 2018 patent	Jun. 11, 2018 EUR (€)	Jun. 11, 2018 USD ($)	May 03, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2019 EUR (€) ft²	Sep. 30, 2019 GBP (£) ft²	Sep. 30, 2019 USD ($) 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								$ 231,000	$ 123,000	$ 121,000
Annual base rent													$ 1,000,000.0
Tenant improvement allowances													1,000,000.0
Unamortized lease incentives													600,000
Rent expense for operating leases								2,100,000	$ 1,700,000	$ 600,000
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%
France
Loss Contingencies [Line Items]
Annual base rent											€ 0.4		400,000
Netherlands
Loss Contingencies [Line Items]
Annual base rent											0.2		200,000
United States
Loss Contingencies [Line Items]
Annual base rent													200,000
Spain
Loss Contingencies [Line Items]
Annual base rent											€ 0.1		100,000
United Kingdom
Loss Contingencies [Line Items]
Annual base rent												£ 63	78,000
Other Current Liabilities
Loss Contingencies [Line Items]
Unamortized lease incentives													100,000
Other Noncurrent Liabilities
Loss Contingencies [Line Items]
Unamortized lease incentives													$ 500,000
Building
Loss Contingencies [Line Items]
Space area subject to lease (in square feet) | ft²											29	29	29
Pending Litigation | General and administrative
Loss Contingencies [Line Items]
Legal fees								$ 800,000
Pending Litigation | Global Equity & Corporate Consulting, S.L.- Breach of Services Agreement | ICAR
Loss Contingencies [Line Items]
Loss contingency, amount claimed					€ 0.8	$ 900,000
Pending Litigation | USAA | Wells Fargo
Loss Contingencies [Line Items]
Number of patents allegedly infringed | patent			5	4
Pending Litigation | USAA | Wells Fargo | Subsequent Event
Loss Contingencies [Line Items]
Number of patents infringed | patent	1
Amount awarded in damages to other party	$ 200,000,000
Pending Litigation | UrbanFT
Loss Contingencies [Line Items]
Number of lawsuits filed | claim		1
Number of customers in delinquent payment | customer		1