Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 56,446		$ 54,538		$ 53,151		$ 48,723		$ 51,612		$ 47,885		$ 45,882		$ 47,322		$ 212,858	$ 192,701	$ 195,381
Gross profit	26,682		25,349		24,078		21,922		23,647		22,149		21,780		22,908		98,031	90,484	100,123
Net income (loss)	$ 2,985	[1],[2],[3]	$ 2,496	[1],[2],[3]	$ 1,446	[1],[2],[3]	$ (339)	[1],[2],[3]	$ 426	[1]	$ (101)	[1]	$ 738	[1]	$ 688	[1]	$ 6,588	$ 1,751	$ 5,805
Net income per common share, basic (USD per share)	$ 0.12		$ 0.10		$ 0.06		$ (0.01)		$ 0.02		$ 0.00		$ 0.03		$ 0.03		$ 0.27	$ 0.07	$ 0.22
Net income per common share, diluted (USD per share)	$ 0.12		$ 0.10		$ 0.06		$ (0.01)		$ 0.02		$ 0.00		$ 0.03		$ 0.03		$ 0.26	$ 0.07	$ 0.22
Net tax benefits
Net tax benefits			$ 400				$ 500				$ 100		$ 1,100		$ 200		$ 900	$ 1,400	$ 800
Restructuring Charges [Abstract]
Restructuring charge					$ 500												518	$ 152	$ 350
Restructuring accrual, net of tax					300
Gain From Settlement of Property and Casualty Claim [Abstract]
Gain from settlement of property and casualty claim			400		1,000												$ 1,400
Gain from settlement of property and casualty claim, net of tax			$ 300		$ 600

[1] During fiscal 2015 and 2014, we recorded net tax benefits of $0.9 million and $1.4 million, respectively. We recorded a benefit of $0.5 million in the first quarter of fiscal 2015 resulting from the reinstatement of the research and development tax credit for calendar year 2014, reversal of income tax reserves due to the expiration of the statute of limitations from various U.S. and foreign tax jurisdictions and reversal of tax reserves due to the resolution of tax audits. In the third quarter of fiscal 2015, we recorded a tax benefit of $0.4 million primarily due to the reversal of reserves for state research and development tax credits and transfer pricing, partially offset by an adjustment of the state rate on net deferred tax assets. We recorded net tax benefits of $0.2 million in the first quarter of fiscal 2014 resulting from the release of income tax reserves due to the expiration of the statute of limitations from various U.S. and foreign tax jurisdictions. During the second quarter of fiscal 2014, we recorded a tax benefit of $1.1 million resulting from re-measurement and reversal of certain income tax reserves as a result of the conclusion of a federal income tax audit for fiscal 2012. In the third quarter of fiscal 2014, we recorded a tax benefit of $0.1 million primarily for a valuation allowance reversal associated with the reassessment of state research and development tax credits.

[2] During fiscal 2015, we recorded a gain of $1.4 million from the settlement of a property and casualty insurance claim related to the replacement of our capital equipment destroyed in the fire at our subcontract manufacturer's location. We recorded $1.0 million ($0.6 million after tax) during the second quarter of fiscal 2015 and $0.4 million ($0.3 million after tax) during the third quarter of fiscal 2015.

[3] In the second quarter of fiscal 2015, we recorded a business restructuring accrual of $0.5 million ($0.3 million after tax).