Calculation of Basic and Diluted Net Income Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Numerator:
Net income	$ 1,985	$ 1,705
Denominator (in thousands):
Weighted-average common stock outstanding	21,159	22,197
Effect of stock options and stock appreciation rights	431	473
Diluted weighted average common stock outstanding	21,590	22,670
Basic and diluted net income per share	$ 0.09	$ 0.08