Stockholders' Equity - Basic and Diluted Net Income Per Common Shares (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net income	$ 854	$ 3,444
Denominator:
Basic weighted average common shares outstanding (shares)	20,530,739	20,706,082
Diluted weighted average common shares outstanding (shares)	20,585,542	20,706,082
Basic and diluted net income per common share (usd per share)	$ 0.04	$ 0.17