Property and Equipment - Component of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Line Items]
Property and equipment	$ 238,330	$ 220,220
Less accumulated depreciation and amortization	139,207	126,725
Property and equipment, net	99,123	93,495
Land and land improvements
Property, Plant and Equipment [Line Items]
Property and equipment	22,590	21,626
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	42,344	39,726
Fleet and Other Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	75,365	71,002
Tanks and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	54,848	47,694
Furniture, Fixtures and Office Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 43,183	$ 40,172