Leases - Summary of Other Information Concerning the Company's Operating Lease (Detail) - USD ($)	Dec. 31, 2021	Sep. 30, 2021	Oct. 09, 2020	Aug. 28, 2020
Lessee, Lease, Description [Line Items]
Current operating lease liability	$ 417,000	$ 393,000
Non-current operating lease liability	308,000	392,000
New Lease Agreement [Member]
Lessee, Lease, Description [Line Items]
Operating lease ROU asset included in other long-term assets			$ 254,000	$ 970,000
Blaw Knox Product Line From Volvo CE [Member] | New Lease Agreement [Member]
Lessee, Lease, Description [Line Items]
Operating lease ROU asset included in other long-term assets	725,000	785,000
Current operating lease liability	417,000	393,000
Non-current operating lease liability	$ 308,000	$ 392,000
Weighted average remaining lease term (in years)	1 year 9 months	2 years
Weighted average discount rate used in calculating ROU asset	4.00%	4.00%