Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenues	$ 115,813	$ 118,062	$ 341,105	$ 403,781
Cost of goods sold	98,646	96,718	288,513	330,926
Gross profit	17,167	21,344	52,592	72,855
Selling, general and administrative expenses	16,710	15,511	50,259	51,372
Research and development expenses	1,772	1,605	5,046	4,863
Amortization of intangible assets	44	44	132	132
Restructuring and other, net	0	1,400	0	1,400
Operating income (loss)	(1,359)	2,784	(2,845)	15,088
Interest expense	51	52	152	179
Interest income	(72)	(190)	(230)	(901)
Income (loss) before income taxes	(1,338)	2,922	(2,767)	15,810
Income tax provision (benefit)	703	(559)	(138)	2,133
Net income (loss)	$ (2,041)	$ 3,481	$ (2,629)	$ 13,677
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.17)	$ 0.30	$ (0.22)	$ 1.18
Diluted (in dollars per share)	$ (0.17)	$ 0.30	$ (0.22)	$ 1.17
Weighted average shares:
Basic (in shares)	11,720	11,631	11,700	11,622
Diluted (in shares)	11,720	11,698	11,700	11,686
Dividends per share (in dollars per share)	$ 0.26	$ 0.26	$ 0.78	$ 0.78