Stockholders' Equity - Basic and Diluted Net Income Per Common Shares (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Equity [Abstract]
Net income	$ 3,444	$ 3,917
Weighted average shares of common stock outstanding (shares)	20,683,719	21,898,792
Dilutive effect of restricted stock and RSUs (shares)	161,942	154,223
Weighted average shares of common stock and common stock equivalents (shares)	20,845,661	22,053,015
Basic net income per common share (usd per share)	$ 0.17	$ 0.18
Diluted net income per common share (usd per share)	$ 0.17	$ 0.18