Warrant Exercises (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Gain on extinguishment of warrant liabilities	$ 0	$ 0	$ 3,520	$ 73,291
Warrants Exercised On May 22, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			May 22, 2013
Market price of common stock:	$ 5.76		$ 5.76
Exercise warrants:			28,348
Exercise price:	$ 3.5		$ 3.5
Remaining contractual life (years):			5 months 8 days
Dividend yield:			0.00%
Expected volatility:			35.48%
Risk-free interest rate:			0.07%
Fair values:			$ 2.2653
Gain on extinguishment of warrant liabilities			3,520
Warrants Exercised On February 7, 2012
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:				Feb. 07, 2012
Market price of common stock:		$ 6.44		$ 6.44
Exercise warrants:				125,000
Exercise price:		$ 3.5		$ 3.5
Remaining contractual life (years):				1 year 8 months 23 days
Dividend yield:				0.00%
Expected volatility:				39.43%
Risk-free interest rate:				0.21%
Fair values:				$ 3.08
Gain on extinguishment of warrant liabilities				$ 73,291