Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]
Beginning balance (in shares) at Sep. 30, 2013		29,982,000
Beginning balance at Sep. 30, 2013	$ 101,179	$ 749,266	$ (2,071)	$ 1,623	$ (647,639)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,852				4,852
Translation adjustment	214			214
Share-based compensation (in shares)		633,000
Stock-based compensation	4,074	$ 4,074
Stock option exercises (in shares)		120,000
Stock option exercises	573	$ 573
Issuance of common stock - ESPP (in shares)		341,000
Issuance of common stock - ESPP	$ 1,182	$ 1,182
Issuance of common stock - ODPP (in shares)	1,600	2,000
Issuance of common stock - ODPP	$ 8	$ 8
Issuance of common stock - Board of Directors (in shares)		31,000
Issuance of common stock - Board of Directors	265	$ 265
Ending balance (in shares) at Sep. 30, 2014		31,109,000
Ending balance at Sep. 30, 2014	112,347	$ 755,368	(2,071)	1,837	(642,787)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	63,100				63,100
Translation adjustment	(990)			(990)
Share-based compensation (in shares)		948,000
Stock-based compensation	4,320	$ 4,320
Stock option exercises (in shares)		290,000
Stock option exercises	1,409	$ 1,409
Purchase of treasury stock (in shares)		(6,870,000)
Purchase of treasury stock	(45,650)		(45,650)
Issuance of common stock - ESPP (in shares)		121,000
Issuance of common stock - ESPP	$ 493	$ 493
Issuance of common stock - ODPP (in shares)	0
Issuance of common stock - Board of Directors (in shares)		78,000
Issuance of common stock - Board of Directors	$ 413	$ 413
Ending balance (in shares) at Sep. 30, 2015	25,676,000	25,676,000
Ending balance at Sep. 30, 2015	$ 135,442	$ 762,003	(47,721)	847	(579,687)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,266				8,266
Translation adjustment	(268)			(268)
Share-based compensation (in shares)		284,000
Stock-based compensation	1,868	$ 1,868
Special dividend paid	$ (39,214)	$ (39,214)
Stock option exercises (in shares)	45,340	45,000
Stock option exercises	$ 225	$ 225
Issuance of common stock - ESPP (in shares)		193,000
Issuance of common stock - ESPP	$ 735	$ 735
Issuance of common stock - ODPP (in shares)	0
Issuance of common stock - Board of Directors (in shares)		46,000
Issuance of common stock - Board of Directors	$ 263	$ 263
Ending balance (in shares) at Sep. 30, 2016	26,244,000	26,244,000
Ending balance at Sep. 30, 2016	$ 107,317	$ 725,880	$ (47,721)	$ 579	$ (571,421)