Components of Net Deferred Taxes (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Deferred tax assets:
Operating lease liabilities	$ 29,997
Net operating loss carryforwards	5,620	$ 6,292
Vacation accrual	2,931	2,774
Pension accrual	3,807	4,504
Allowance for bad debts	1,653	2,235
Insurance accrual	2,283	2,419
Inventory capitalization	641	247
Fair value of derivative instruments	3,556	2,794
Other, net	1,208
Total deferred tax assets	51,696	21,265
Valuation allowance	(3,890)	(4,003)
Net deferred tax assets	47,806	17,262
Deferred tax liabilities:
Operating lease right-of-use assets	28,492
Property and equipment	14,305	13,485
Intangibles	19,091	21,883
Other, net	3,145	2,010
Total deferred tax liabilities	65,033	37,378
Net deferred taxes	$ (17,227)	$ (20,116)