Summary of Significant Accounting Policies (Net Income Per Common Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2010		Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Accounting Policies [Abstract]
Net income	$ 2,462	[1],[2]	$ 2,307	[1],[2]	$ 2,122	[1],[2]	$ 724	[1],[2]	$ 2,849	[1],[2]	$ 3,615	[1],[2]	$ 2,239	[1],[2]	$ 2,316	[1],[2]	$ 7,615	$ 11,019	$ 8,941
Denominator for basic net income per common share — weighted average shares outstanding																	25,743,000	25,312,000	24,865,000
Effect of dilutive securities [Abstract]
Employee stock options and employee stock purchase plan																	403,000	507,000	289,000
Denominator for diluted net income per common share — adjusted weighted average shares																	26,146,000	25,819,000	25,154,000
Net income per common share, basic	$ 0.10		$ 0.09		$ 0.08		$ 0.03		$ 0.11		$ 0.14		$ 0.09		$ 0.09		$ 0.30	$ 0.44	$ 0.36
Net income per common share, diluted	$ 0.09		$ 0.09		$ 0.08		$ 0.03		$ 0.11		$ 0.14		$ 0.09		$ 0.09		$ 0.29	$ 0.43	$ 0.36
Antidilutive securities excluded from computation of earnings per share																	2,023,213	1,831,713	2,493,261

[1] During fiscal 2012, we recorded a business restructuring accrual of $0.2 million ($0.2 million after tax) in the first quarter, $0.1 million ($0.0 million after tax) in the second quarter and $1.0 million ($0.6 million after tax) in the third quarter. We reversed a business restructuring accrual of $0.1 million ($0.0 million after tax) in the first quarter of fiscal 2011 and recorded a restructuring charge of $0.2 million ($0.1 million after tax) during the fourth quarter of fiscal 2011.

[2] During fiscal 2012 and 2011, we recorded discrete tax benefits of $1.5 million and $0.7 million, respectively. We recorded a benefit of $0.1 million in the first quarter of fiscal 2012 resulting from the release of income tax reserves due to the expiration of the statutes of limitations from various U.S. tax jurisdictions. During the third quarter of fiscal 2012, we recorded $1.1 million for additional research and development tax credits identified for fiscal years ended September 30, 2009, 2010 and 2011 from a recently completed research and development tax credit study. During the fourth quarter of fiscal 2012, we recorded $0.3 million relating to expiration of statue of limitations. During fiscal 2011, we recorded $0.6 million in the first quarter and $0.1 million in the fourth quarter resulting from the reversal of previously established income tax reserves from various jurisdictions, primarily foreign, for the expiration of statute of limitations and from the enactment of the Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010 providing for the extension of the research and development tax credit.