Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]
Net income	$ 1,000	$ 2,122	$ 2,230	$ 2,846
Denominator for basic net income per common share — weighted average shares outstanding	26,138,000	25,709,000	26,163,000	25,674,000
Effect of dilutive securities [Abstract]
Employee stock options, restricted stock units and employee stock purchase plan	338,000	496,000	311,000	498,000
Denominator for diluted net income per common share — adjusted weighted average shares	26,476,000	26,205,000	26,474,000	26,172,000
Net income per common share, basic	$ 0.04	$ 0.08	$ 0.09	$ 0.11
Net income per common share, diluted	$ 0.04	$ 0.08	$ 0.08	$ 0.11
Antidilutive securities excluded from computation of earnings per share	3,263,692	1,798,213	2,502,985	1,798,213