Business Combinations - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended		12 Months Ended			28 Months Ended
	Oct. 16, 2017	Jan. 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2020	Dec. 31, 2019	Apr. 30, 2018
Business Acquisition [Line Items]
Consideration paid for acquisition, net of cash acquired					$ 0	$ 0	$ 29,744,000
Acquisition-related costs and expenses					6,575,000	7,563,000	8,239,000
Earnout consideration liability					753,000	1,601,000		$ 753,000
Payment for contingent consideration liability					478,000	$ 1,030,000	1,284,000
Revenue from business combinations							9,100,000
Net loss from business combinations							5,300,000
A2iA
Business Acquisition [Line Items]
Consideration paid for acquisition, net of cash acquired								$ 26,800,000
Acquisition-related shares issued (in shares)								2,514,588
Value of common stock issued during acquisition								$ 21,900,000
Transaction-related liabilities								200,000
Acquisition-related costs and expenses							$ 2,200,000
Payments for cash for collateral								$ 700,000
Payments for collateral, equity (in shares)								508,479
Payments for collateral, equity, value								$ 4,400,000
Period to maintain escrow funds								24 months
Claims against the escrow funds								$ 0
ICAR
Business Acquisition [Line Items]
Consideration paid for acquisition, net of cash acquired	$ 3,000,000.0
Acquisition-related shares issued (in shares)	584,291
Value of common stock issued during acquisition	$ 5,600,000
Earnout consideration liability	2,900,000
Acquisition transaction costs	500,000
Escrow deposit	1,500,000								$ 1,000,000.0	$ 1,500,000
ICAR | Q4 Consideration
Business Acquisition [Line Items]
Maximum earnout consideration	1,500,000
ICAR | Earnout Consideration
Business Acquisition [Line Items]
Maximum earnout consideration	3,800,000
Earnout consideration liability					$ 1,800,000			$ 1,800,000
Payment for contingent consideration liability		$ 1,800,000		$ 1,100,000
ICAR | Earnout Consideration | Subsequent Event | Forecast
Business Acquisition [Line Items]
Payment for contingent consideration liability			$ 800,000
ICAR | Maximum
Business Acquisition [Line Items]
Aggregate purchase price	$ 13,900,000