Commitments and Contingencies - Additional Information (Details) - USD ($)			3 Months Ended	6 Months Ended	12 Months Ended
	Nov. 13, 2018	Jul. 27, 2018	Mar. 31, 2020	Mar. 31, 2020	Sep. 30, 2019	Apr. 30, 2020
Commitments And Contingencies [Line Items]
Contingent earn-out liability			$ 10,912,000	$ 10,912,000	$ 9,940,000
Adjustment to initial contingent earn-out liability			972,000	972,000
Future minimum lease obligations, remainder of fiscal year 2020			83,000	83,000
Future minimum lease obligations, fiscal year 2021			84,000	84,000
Office Space and Certain Equipment
Commitments And Contingencies [Line Items]
Future minimum lease obligations, remainder of fiscal year 2020			100,000	100,000
Future minimum lease obligations, fiscal year 2021			$ 100,000	$ 100,000
Maximum | Office Space and Certain Equipment
Commitments And Contingencies [Line Items]
Operating lease term			2 years	2 years
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				$ 1,500,000	(2,900,000)
Estimated fair value of earn-out liability			$ 6,300,000	6,300,000	4,800,000
Quantum | U.S. Customs and Border Protection U.S. Border Patrol | Subsequent Event
Commitments And Contingencies [Line Items]
Awarded contract amount						$ 10,000,000
OptoSeis® Fiber Optic Sensing Technology Business
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				(500,000)	800,000
Estimated fair value of earn-out liability			$ 4,600,000	$ 4,600,000	$ 5,100,000