Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenues	$ 85,927,000	$ 133,207,000	$ 300,948,000	$ 435,450,000
Cost of goods sold	76,873,000	105,922,000	261,073,000	354,921,000
Gross profit	9,054,000	27,285,000	39,875,000	80,529,000
Selling, general and administrative expenses	14,761,000	19,362,000	46,453,000	57,787,000
Research and development expenses	1,726,000	1,640,000	4,818,000	5,453,000
Amortization of intangible assets	87,000	89,000	263,000	263,000
Restructuring and separation costs	0	647,000	840,000	7,703,000
Operating income (loss)	(7,520,000)	5,547,000	(12,499,000)	9,323,000
Other income	(507,000)	(507,000)	(1,522,000)	(1,522,000)
Interest expense	41,000	38,000	122,000	112,000
Interest income	(156,000)	(42,000)	(287,000)	(113,000)
Income (loss) before income taxes	(6,898,000)	6,058,000	(10,812,000)	10,846,000
Income tax provision (benefit)	(3,683,000)	1,164,000	(6,469,000)	844,000
Net income (loss)	$ (3,215,000)	$ 4,894,000	$ (4,343,000)	$ 10,002,000
Income (loss) per share:
Basic (in dollars per share)	$ (0.28)	$ 0.43	$ (0.38)	$ 0.88
Diluted (in dollars per share)	$ (0.28)	$ 0.43	$ (0.38)	$ 0.87
Weighted average shares:
Basic (in shares)	11,463	11,397	11,449	11,387
Diluted (in shares)	11,463	11,473	11,449	11,435
Dividends per share (in dollars per share)	$ 0.26	$ 0.26	$ 0.78	$ 0.78