Calculation of Basic and Diluted Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator:
Net income (loss)	$ 6,267	$ (819)	$ 6,685
Denominator (in thousands):
Basic weighted-average common stock outstanding	20,480	20,622	22,009
Effect of stock options, stock appreciation rights and restricted stock units	509		456
Diluted weighted-average common stock outstanding	20,989	20,622	22,465
Basic net income (loss) per share	$ 0.31	$ (0.04)	$ 0.30
Diluted net income (loss) per share	$ 0.30	$ (0.04)	$ 0.30