Leases - Summary of Other Information Concerning the Company's Operating Lease (Detail) - USD ($)	Jun. 30, 2024	Sep. 30, 2023	Aug. 28, 2020
Lessee, Lease, Description [Line Items]
Current operating lease liability	$ 359,000	$ 328,000
Non-current operating lease liability	61,000
New Lease Agreement [Member]
Lessee, Lease, Description [Line Items]
Operating lease ROU asset included in other long-term assets	420,000	328,000	$ 970,000
Blaw Knox Product Line From Volvo CE [Member] | New Lease Agreement [Member]
Lessee, Lease, Description [Line Items]
Current operating lease liability	359,000	328,000
Non-current operating lease liability	$ 61,000	$ 0
Weighted average remaining lease term (in years)	1 year 2 months 1 day	6 months 3 days
Weighted average discount rate used in calculating ROU asset	5.00%	4.50%