Revenue Recognition - Additional Information (Details) - USD ($)	3 Months Ended							6 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Unbilled receivables										$ 1,051,000
Deferred contract liabilities	$ 0							$ 0		0
Revenue	21,565,000			$ 21,604,000				34,597,000	$ 48,326,000
Cost of revenue	17,890,000			23,045,000				34,179,000	44,780,000
Value of notes with customer	16,106,000							16,106,000		$ 7,896,000
Secured Promissory Note
Disaggregation Of Revenue [Line Items]
Value of notes with customer	$ 8,000,000.0	$ 3,700,000					$ 10,000,000.0	8,000,000.0
Term of the notes	1 year	9 months	6 months				3 years
Monthly principal and interest payments							$ 300,000
Frequency of payments							monthly
Product
Disaggregation Of Revenue [Line Items]
Revenue					$ 0			12,500,000
Cost of revenue					$ 0
Partially financed product sale							$ 12,500,000
Payments received from customer								8,100,000
Deferred Contract Liability
Disaggregation Of Revenue [Line Items]
Revenue	$ 0			0				0	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
Increase in contract amount						$ 300,000
Revenue recognized under the contract								400,000	$ 8,900,000
Revenue for unsatisfied performance obligations	$ 0							$ 0