Commitments and Contingencies - Additional Information (Details) - USD ($)			12 Months Ended
	Nov. 13, 2018	Jul. 27, 2018	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Apr. 30, 2020
Commitments And Contingencies [Line Items]
Contingent earn-out liability			$ 10,962,000	$ 9,940,000
Adjustment to initial contingent earn-out liability			1,100,000	(2,115,000)
Cash contingent earn-out payments			78,000
Rent expense under Operating Leases			500,000	600,000
Future minimum lease obligations (all in fiscal year 2021)			$ 84,000
Maximum
Commitments And Contingencies [Line Items]
Operating lease term			2 years
U.S. Customs and Border Protection U.S. Border Patrol
Commitments And Contingencies [Line Items]
Awarded contract amount					$ 10,700,000
Quantum
Commitments And Contingencies [Line Items]
Contingent earn-out liability		$ 7,700,000
Contingent payments earn-out period		4 years
Contingent payments earn-out period ending month and year		2022-07
Contingent payments maximum earn-out amount		$ 23,500,000
Adjustment to initial contingent earn-out liability			$ 1,100,000	(2,900,000)
Estimated fair value of earn-out liability			5,800,000	4,800,000
Cash contingent earn-out payments			100,000
Quantum | U.S. Customs and Border Protection U.S. Border Patrol
Commitments And Contingencies [Line Items]
Awarded contract amount						$ 10,000,000
Optoseis Technology
Commitments And Contingencies [Line Items]
Contingent earn-out liability	$ 4,300,000
Contingent payments earn-out period	5 years 6 months
Contingent payments earn-out period ending month and year	2024-05
Contingent payments maximum earn-out amount	$ 23,200,000
Adjustment to initial contingent earn-out liability			100,000	800,000
Estimated fair value of earn-out liability			$ 5,200,000	$ 5,100,000