CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenues	$ 470,559	$ 518,499	$ 517,180
Cost of goods sold	395,496	423,924	430,204
Gross profit	75,063	94,575	86,976
Selling, general and administrative expenses	67,217	67,662	69,950
Research and development expenses	6,670	6,265	6,327
Amortization of intangible assets	157	177	177
Insurance proceeds	0	0	(950)
Restructuring and other, net	0	1,400	11
Operating income	1,019	19,071	11,461
Other income	0	(506)	0
Interest expense	204	228	230
Interest income	(277)	(981)	(1,103)
Income before income taxes	1,092	20,330	12,334
Income tax provision	461	3,670	2,444
Net income	$ 631	$ 16,660	$ 9,890
Earnings per share:
Basic (in dollars per share)	$ 0.05	$ 1.43	$ 0.85
Diluted (in dollars per share)	$ 0.05	$ 1.42	$ 0.85
Weighted average shares:
Basic (in shares)	11,705	11,624	11,571
Diluted (in shares)	11,789	11,693	11,634
Dividends per share (in dollars per share)	$ 1.04	$ 1.04	$ 1.04