Movements of Options Issued and Outstanding (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2013		Dec. 31, 2012
Number of Underlying Shares
Number of underlying shares, Outstanding at beginning of the period	715,000
Granted	60,000
Exercised	0
Expired	0
Forfeited	0
Number of underlying shares, Outstanding at end of the period	775,000		715,000
Number of Underlying Shares, Exercisable at June 30, 2013	445,000
Weighted Average Exercise Price Per Share
Weighted- Average Exercise Price Per Share, Outstanding at beginning of the period	$ 5.25
Granted	$ 5.60
Weighted- Average Exercise Price Per Share, Outstanding at end of the period	$ 5.28		$ 5.25
Weighted Average Exercise Price Per Share, Exercisable at June 30, 2013	$ 5.71
Aggregate Intrinsic Value
Aggregate Intrinsic Value(1), Outstanding at beginning of the period	$ 65,700	[1]
Aggregate Intrinsic Value(1), Outstanding at end of the period	222,450	[1]	65,700	[1]
Aggregate Intrinsic Value, Exercisable at June 30, 2013	$ 138,750	[1]
Weighted Average Contractual Life Remaining in Years
Weighted- Average Contractual Life Remaining in Years Outstanding	8 years 2 months 1 day		8 years 5 months 19 days
Granted	10 years
Weighted-Average Contractual Life Remaining in Years, Exercisable at June 30, 2013	7 years 10 months 2 days

[1] The intrinsic value of the stock options at June 30, 2013 and January 1, 2013 is the amount by which the market value of the Company’s common stock of $4.81 and $4.39, as of June 30, 2013 and January 1, 2013, respectively, exceeds the exercise price of the option.