Revenue Recognition and Related Costs - Disaggregation of Company's Net Revenue by Major Source (Detail) - USD ($)	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Disaggregation of Revenue [Line Items]
Net revenue	$ 23,577,000	$ 31,416,000
Equipment Sales [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net revenue	9,295,000	16,831,000
Equipment Sales [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net revenue	5,904,000	7,588,000
Parts and Component Sales [Member]
Disaggregation of Revenue [Line Items]
Net revenue	6,746,000	6,151,000
Freight Revenue [Member]
Disaggregation of Revenue [Line Items]
Net revenue	1,574,000	745,000
Other [Member]
Disaggregation of Revenue [Line Items]
Net revenue	$ 58,000	$ 101,000