Net Income Per Share - Summary of Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 6,953	$ 5,200	$ 12,955	$ 10,438
Weighted average shares outstanding	19,215	17,779	19,064	17,700
Effective of dilutive stock options	367	393	352	354
Diluted shares outstanding	19,582	18,172	19,416	18,054
Basic net income per share	$ 0.36	$ 0.29	$ 0.68	$ 0.59
Diluted net income per share	$ 0.36	$ 0.29	$ 0.67	$ 0.58