Revenue Recognition - Additional Information (Details) - USD ($)	3 Months Ended					9 Months Ended		12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Unbilled receivables	$ 1,561,000					$ 1,561,000
Deferred contract costs	0					0		$ 0
Revenue	17,679,000			$ 6,975,000		66,005,000	$ 25,575,000
Cost of revenue	17,456,000			14,639,000		62,236,000	47,849,000
Value of notes with customer	8,682,000					$ 8,682,000		184,000
Secured Promissory Note
Disaggregation Of Revenue [Line Items]
Value of notes with customer					$ 10,000,000.0
Term of the notes					3 years
Monthly principal and interest payments					$ 300,000
Frequency of payments					monthly	monthly
Product
Disaggregation Of Revenue [Line Items]
Revenue		$ 12,500,000	$ 0
Cost of revenue			$ 0
Partially financed product sale					$ 12,500,000
Payments received from customer						$ 7,000,000.0
Deferred Revenue and Other Liabilities
Disaggregation Of Revenue [Line Items]
Deferred contract liabilities	0					0		200,000
Deferred Contract Liability
Disaggregation Of Revenue [Line Items]
Revenue	0			0		200,000	0
Cost of revenue	0			0		0	0
U.S. Customs and Border Protection ("CBP")
Disaggregation Of Revenue [Line Items]
Awarded contract amount				10,500,000			$ 10,500,000
Increase in contract amount				$ 300,000
Revenue recognized under the contract						9,900,000		$ 300,000
Unbilled receivables	1,500,000					1,500,000
Revenue for unsatisfied performance obligations	$ 300,000					$ 300,000