CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues	$ 395,911	$ 565,243	$ 661,858
Cost of goods sold	345,142	459,038	553,597
Gross profit	50,769	106,205	108,261
Selling, general and administrative expenses	61,524	74,924	76,801
Research and development expenses	6,906	6,731	6,980
Amortization of intangible assets	355	352	435
Restructuring and separation expenses	1,322	8,441	3,397
Operating income (loss)	(19,338)	15,757	20,648
Other income (See Note E)	(2,029)	(2,029)	(2,402)
Interest expense	168	149	145
Interest income	(558)	(156)	(86)
Income (loss) before income taxes	(16,919)	17,793	22,991
Income tax provision (benefit)	(7,433)	2,283	13,552
Net income (loss)	$ (9,486)	$ 15,510	$ 9,439
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.83)	$ 1.36	$ 0.80
Diluted (in dollars per share)	$ (0.83)	$ 1.36	$ 0.79
Weighted average shares:
Basic (in shares)	11,453	11,400	11,869
Diluted (in shares)	11,453	11,431	11,908
Dividends per share (in dollars per share)	$ 1.04	$ 1.04	$ 1.04