Movements of Options Issued and Outstanding (Detail) (USD $)	6 Months Ended
	Jun. 30, 2012
Number of Underlying Shares
Outstanding at December 31, 2011	715,000
Granted	60,000
Exercised
Expired
Forfeited
Outstanding at June 30, 2012	775,000
Exercisable at June 30, 2012	190,000
Weighted Average Exercise Price Per Share
Outstanding at December 31, 2011	$ 5.16
Granted	$ 5.63
Outstanding at June 30, 2012	$ 5.19
Exercisable at June 30, 2012	$ 6.97
Aggregate Intrinsic Value
Outstanding at December 31, 2011	$ 213,300	[1]
Outstanding at June 30, 2012	612,900	[1]
Exercisable at June 30, 2012	$ 98,400	[1]
Weighted Average Contractual Life Remaining in Years
Outstanding at December 31, 2011	9 years 5 months 5 days
Granted	10 years
Outstanding at June 30, 2012	9 years
Exercisable at June 30, 2012	7 years 10 months 10 days

[1] The intrinsic value of the stock options at June 30, 2012 and December 31, 2011 is the amount by which the market value of the Company's common stock of $5.48 and $4.76, as of June 30, 2012 and December 31, 2011, respectively, exceeds the exercise price of the option.