Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenues	$ 122,130	$ 85,927	$ 313,819	$ 300,948
Cost of goods sold	103,755	76,873	272,469	261,073
Gross profit	18,375	9,054	41,350	39,875
Selling, general and administrative expenses	16,174	14,761	48,462	46,453
Research and development expenses	1,632	1,726	4,926	4,818
Amortization of intangible assets	44	87	161	263
Restructuring and separation expenses	0	0	0	840
Operating income (loss)	525	(7,520)	(12,199)	(12,499)
Other income	0	(507)	(507)	(1,522)
Interest expense	51	41	153	122
Interest income	(215)	(156)	(711)	(287)
Income (loss) before income taxes	689	(6,898)	(11,134)	(10,812)
Income tax provision (benefit)	388	(3,683)	(2,443)	(6,469)
Net income (loss)	$ 301	$ (3,215)	$ (8,691)	$ (4,343)
Income (loss) per share:
Basic (in dollars per share)	$ 0.03	$ (0.28)	$ (0.76)	$ (0.38)
Diluted (in dollars per share)	$ 0.03	$ (0.28)	$ (0.76)	$ (0.38)
Weighted average shares:
Basic (in shares)	11,514	11,463	11,503	11,449
Diluted (in shares)	11,587	11,463	11,503	11,449
Dividends per share (in dollars per share)	$ 0.26	$ 0.26	$ 0.78	$ 0.78