Annual report pursuant to Section 13 and 15(d)

Provision for Income Taxes - Additional Information (Detail)

v3.20.2
Provision for Income Taxes - Additional Information (Detail) - USD ($)
Sep. 30, 2020
Sep. 30, 2019
Income Tax Contingency [Line Items]    
Deferred tax assets, gross $ 3,772,000 $ 3,574,000
Fuel tax credits 300,000 300,000
Goodwill expected to be deductible to tax purposes 22,600,000 19,000,000.0
Unrecognized tax benefits 0 0
State    
Income Tax Contingency [Line Items]    
Operating loss carryforwards $ 15,300,000 $ 31,600,000