Net Income per Share - Computation of Basic and Diluted Net Income per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic:
Net income available for common stockholders	$ 721	$ 663	$ 2,456	$ 1,873
Weighted-average shares outstanding	15,339	15,130	15,262	15,208
Basic earnings per share	$ 0.05	$ 0.04	$ 0.16	$ 0.12
Diluted:
Net income available for common stockholders	$ 721	$ 663	$ 2,456	$ 1,873
Weighted-average shares outstanding	15,339	15,130	15,262	15,208
Common stock equivalents, if diluted	441	475	445	446
Shares used in computing diluted earnings per common share	15,780	15,605	15,707	15,654
Diluted earnings per share	$ 0.05	$ 0.04	$ 0.16	$ 0.12
Shares excluded in computing diluted earnings per share as those shares would be anti-dilutive	395	523	438	559