Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, deposit in Billions	3 Months Ended			9 Months Ended
	Jun. 30, 2019 USD ($) deposit patent institution $ / shares	Sep. 30, 2018 USD ($) $ / shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) segment patent institution deposit $ / shares	Jun. 30, 2018 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of financial institutions signed agreements to deploy mobile deposit (more than) | institution	6,600			6,600
Number of check deposits processed (more than) | deposit	3			3
Number of patents granted | patent	51			51
Number of pending patent applications | patent	19			19
Net (loss) gain resulting from foreign exchange translation	$ 814,000		$ (942,000)	$ (1,213,000)	$ (350,000)
Other-than-temporary impairments recognized on investments	0		0	0	0
Write-offs of allowance for doubtful accounts				100,000	0
Allowance for doubtful accounts receivable	200,000	$ 300,000		200,000
Capitalized software development costs	$ 0		$ 0	0	0
Amortization expense of capitalized software development costs				0	0
Capitalized software development costs for internal use				200,000	600,000
Amortization expense from capitalized software development costs for internal use				$ 300,000	$ 0
Number of operating segments | segment				1
Number of reporting units | segment				1
Goodwill impairment		$ 0
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001		$ 0.001
Trading-day average stock price period				20 days
Accumulated other comprehensive loss	$ 1,773,000	$ 586,000		$ 1,773,000
Minimum | ICAR | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term of loan agreement				5 years
Amount outstanding under loan agreement	600,000	800,000		$ 600,000
Minimum | ICAR | Spanish Government Agencies | Other current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount outstanding under loan agreement	200,000	300,000		200,000
Minimum | ICAR | Spanish Government Agencies | Other non-current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount outstanding under loan agreement	$ 500,000	$ 500,000		$ 500,000
Maximum | ICAR | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term of loan agreement				12 years
Interest rate on loan agreement	0.00%			0.00%