Net Income Per Share - Components and Computation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator
Net income	$ 11,449	$ 11,407	$ 31,832	$ 32,116
Denominator
Weighted average common shares outstanding, basic	35,961	35,295	35,873	35,133
Options to purchase common stock	520	578	533	596
PSUs, RSUs, RSAs, and DSUs	534	493	492	408
Weighted average common shares outstanding, diluted	37,015	36,366	36,898	36,137
Net income per share
Basic	$ 0.32	$ 0.32	$ 0.89	$ 0.91
Diluted	$ 0.31	$ 0.31	$ 0.86	$ 0.89