Components of Net Deferred Taxes and Related Valuation Allowance (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Deferred tax assets:
Net operating loss carryforwards	$ 6,760	$ 8,626
Vacation accrual	2,580	2,586
Pension accrual	2,672	5,201
Allowance for bad debts	3,158	2,845
Fair value of derivative instruments	2,314
Insurance accrual	21,073	18,085
Inventory	941	869
Alternative minimum tax credit carryforward	261	261
Other, net	1,906	2,188
Total deferred tax assets	41,665	40,661
Valuation allowance		(658)
Net deferred tax assets	41,665	40,003
Deferred tax liabilities:
Property and equipment	2,225	1,947
Intangibles	26,285	20,164
Fair value of derivative instruments		484
Total deferred tax liabilities	28,510	22,595
Net deferred taxes	$ 13,155	$ 17,408