Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 513	$ 537	$ 310
Charged to Costs and Expenses	583	34	347
Deductions	(34)	(75)	(100)
Other	16	17	(20)
Balance at End of Period	1,078	513	537
Inventory Realizability Reserves [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	3,629	2,441	1,971
Charged to Costs and Expenses	2,703	1,775	930
Deductions	(1,297)	(564)	(448)
Other	(38)	(23)	(12)
Balance at End of Period	4,997	3,629	2,441
Valuation Allowances - Deferred Taxes [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	895	666	302
Charged to Costs and Expenses	729	335	364
Deductions	0	(106)
Other			0
Balance at End of Period	$ 1,624	$ 895	$ 666