Component of Property and Equipment and their Estimated Useful Lives (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Property, Plant and Equipment [Line Items]
Property and equipment	$ 170,462	$ 167,060
Less accumulated depreciation	119,139	114,452
Property and equipment, net	51,323	52,608
Land and Land Improvements
Property, Plant and Equipment [Line Items]
Property and equipment	13,958	13,904
Building And Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment	27,571	27,354
Fleet and Other Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	46,260	47,742
Tanks and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	21,445	18,792
Furniture and Fixtures and Office Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 61,228	$ 59,268