Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2015
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 45,105		$ 45,739		$ 45,615		$ 45,175		$ 50,454		$ 52,130		$ 50,162		$ 50,259		$ 181,634	$ 203,005		$ 203,847
Gross profit	21,334		22,485		21,902		21,453		24,604		25,977		24,742		24,357		87,174	99,680		97,121
Income from continuing operations	4,343	[1],[2]	1,335	[1],[2]	1,331	[1],[2]	2,357	[1],[2]	3,844	[1],[2]	4,277	[1],[2]	2,226	[1],[2]	3,131	[1],[2]	9,366	13,478		9,433
Income (loss) from discontinued operations, after income taxes	0		0		0		0		0		0		(89)		3,319		0	3,230		(2,845)
Net income	$ 4,343	[1],[2]	$ 1,335	[1],[2]	$ 1,331	[1],[2]	$ 2,357	[1],[2]	$ 3,844	[1],[2]	$ 4,277	[1],[2]	$ 2,137	[1],[2]	$ 6,450	[1],[2]	$ 9,366	$ 16,708		$ 6,588
Continuing operations	$ 0.16		$ 0.05		$ 0.05		$ 0.09		$ 0.15		$ 0.17		$ 0.09		$ 0.12		$ 0.35	$ 0.52		$ 0.38
Discontinued operations	0.00		0.00		0.00		0.00		0.00		0.00		0.00		0.13		0.00	0.13		(0.12)
Net income per common share, basic (USD per share)	0.16		0.05		0.05		0.09		0.15		0.17		0.08		0.25		0.35	0.65		0.27	[3]
Continuing operations	0.16		0.05		0.05		0.09		0.14		0.16		0.09		0.12		0.35	0.51		0.37
Discontinued operations	0.00		0.00		0.00		0.00		0.00		0.00		0.00		0.13		0.00	0.12		(0.11)
Net income per common share, diluted (USD per share)	$ 0.16		$ 0.05		$ 0.05		$ 0.09		$ 0.14		$ 0.16		$ 0.08		$ 0.25		$ 0.35	$ 0.64	[3]	$ 0.26

[1] During fiscal 2017 and 2016, we recorded net tax benefits of $1.0 million and $1.5 million, respectively. We recorded a benefit of $0.1 million in the first quarter of fiscal 2017 resulting from the reversal of income tax reserves due to the 18. QUARTERLY FINANCIAL DATA (UNAUDITED)(CONTINUED)expiration of the statutes of limitation from various U.S. and foreign tax jurisdictions. In the third quarter of fiscal 2017, we recorded a tax benefit of $0.7 million from the reversal of income tax reserves due to the expiration of the statutes of limitation from various U.S. and foreign tax jurisdictions. In the fourth quarter of fiscal 2017, we recorded a net tax benefit of $0.2 million, primarily from the reversal of income tax reserves due to the expiration of the statutes of limitation from various U.S. and foreign tax jurisdictions and state and foreign prior year true-up provision to return. We recorded a benefit of $0.7 million in the first quarter of fiscal 2016 resulting from the reinstatement of the research and development tax credit for calendar year 2015, reversal of income tax reserves due to the expiration of the statutes of limitation 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 2016, we recorded a tax benefit of $0.5 million primarily due to the filing of an amended income tax return resulting in a domestic refund related to qualified manufacturing activities. In the fourth quarter of fiscal 2016, we recorded a net tax benefit of $0.2 million, primarily due to the filing of an additional amended income tax return resulting in an additional domestic refund related to qualified manufacturing activities, partially offset by an adjustment of the state rate on net deferred tax assets.

[2] For continuing operations, we recorded business restructuring charges of $2.5 million ($1.6 million after tax) in the third quarter of fiscal 2017, $0.7 million ($0.4 million after tax) in the first quarter of fiscal 2016 and $0.1 million ($0.1 million after tax) in the second quarter of fiscal 2016.

[3] Earnings per share presented are calculated by line item and may not add due to the use of rounded amounts.