Nature of Operations and Summary of Significant Accounting Policies - Calculation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share Basic And Diluted [Abstract]
Net income	$ 739	$ 917	$ 999	$ 1,571
Weighted-average common shares outstanding - basic	31,823,386	30,764,694	31,477,723	30,704,250
Weighted-average common shares outstanding - diluted	34,531,964	31,645,696	33,461,787	31,389,569
Net income per share - Basic	$ 0.02	$ 0.03	$ 0.03	$ 0.05
Net income per share - Diluted	$ 0.02	$ 0.03	$ 0.03	$ 0.05