Nature of Operations and Summary of Significant Accounting Policies - Narrative (Details) $ / shares in Units, check_deposit in Billions	3 Months Ended
	Dec. 31, 2020 USD ($) institution patent segment check_deposit $ / shares	Sep. 30, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of financial institutions signed agreements to deploy mobile deposit (more than) | institution	7,500
Number of check deposits processed (more than) | check_deposit	4
Number of patents granted | patent	69
Number of pending patent applications | patent	17
Net gain resulting from foreign exchange translation	$ 2,760,000		$ 1,253,000
Research and development	6,165,000		5,292,000
Other than temporary impairments recognized on investments	0		0
Write-offs of allowance for doubtful accounts	1,000		0
Allowance for doubtful accounts receivable	200,000	$ 200,000
Capitalized software development costs	0		0
Amortization expense of capitalized software development costs	0		0
Capitalized software development costs for internal use	200,000		23,000
Amortization expense from capitalized software development costs for internal use	$ 100,000		100,000
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
Impairment charges related to intangible assets	$ 0		0
Trading-day average stock price period	20 days
Accumulated other comprehensive income (loss)	$ 2,384,000	$ (323,000)
Revision of Prior Period, Reclassification, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Research and development			$ 700,000
ICAR | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest rate on loan agreement	0.00%
Amount outstanding under loan agreement	$ 700,000	700,000
ICAR | Spanish Government Agencies | Other current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount outstanding under loan agreement	100,000	100,000
ICAR | Spanish Government Agencies | Other non-current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount outstanding under loan agreement	$ 600,000	$ 600,000
Minimum | ICAR | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term of loan agreement	5 years
Maximum | ICAR | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term of loan agreement	12 years