Warrant Exercises (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Gain (loss) on extinguishment of warrant liabilities	$ (8,369)	$ 73,291	$ 88,777
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
Exercise warrants:	28,348
Exercise price:	$ 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 (loss) 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
Exercise warrants:		125,000
Exercise price:		$ 3.50
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 (loss) on extinguishment of warrant liabilities		73,291
Warrants Exercised on January 14, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			Jan. 14, 2011
Market price of common stock:			$ 10.64
Exercise warrants:			549,300
Exercise price:			$ 3.50
Remaining contractual life (years):			2 years 9 months 14 days
Dividend yield:			0.00%
Expected volatility:			46.34%
Risk-free interest rate:			0.90%
Fair values:			$ 7.2301
Gain (loss) on extinguishment of warrant liabilities			48,210
Warrants Exercised on March 3, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			Mar. 03, 2011
Market price of common stock:			$ 10.98
Exercise warrants:			20,000
Exercise price:			$ 3.50
Remaining contractual life (years):			2 years 7 months 28 days
Dividend yield:			0.00%
Expected volatility:			48.00%
Risk-free interest rate:			1.09%
Fair values:			$ 7.7083
Gain (loss) on extinguishment of warrant liabilities			8,153
Warrants Exercised on March 14, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			Mar. 14, 2011
Market price of common stock:			$ 10.19
Exercise warrants:			28,814
Exercise price:			$ 4.80
Remaining contractual life (years):			3 years 5 months 19 days
Dividend yield:			0.00%
Expected volatility:			44.05%
Risk-free interest rate:			1.27%
Fair values:			$ 6.0599
Gain (loss) on extinguishment of warrant liabilities			5,722
Warrants Exercised on March 17, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			Mar. 17, 2011
Market price of common stock:			$ 9.79
Exercise warrants:			74,000
Exercise price:			$ 3.50
Remaining contractual life (years):			2 years 7 months 13 days
Dividend yield:			0.00%
Expected volatility:			48.54%
Risk-free interest rate:			0.86%
Fair values:			$ 6.5324
Gain (loss) on extinguishment of warrant liabilities			(1,361)
Warrants Exercised on April 7, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			Apr. 07, 2011
Market price of common stock:			$ 8.39
Exercise warrants:			44,850
Exercise price:			$ 4.80
Remaining contractual life (years):			3 years 4 months 28 days
Dividend yield:			0.00%
Expected volatility:			44.05%
Risk-free interest rate:			1.46%
Fair values:			$ 4.4485
Gain (loss) on extinguishment of warrant liabilities			26,531
Warrants Exercised on December 21, 2011
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:			Dec. 21, 2011
Market price of common stock:			$ 5.00
Exercise warrants:			12,500
Exercise price:			$ 3.50
Remaining contractual life (years):			1 year 10 months 10 days
Dividend yield:			1.19%
Expected volatility:			39.58%
Risk-free interest rate:			0.22%
Fair values:			$ 1.7342
Gain (loss) on extinguishment of warrant liabilities			1,522
Warrants Exercised on September 27, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:	Sep. 27, 2013
Market price of common stock:	$ 4.96
Exercise warrants:	58,000
Exercise price:	$ 3.5
Remaining contractual life (years):	1 month 2 days
Dividend yield:	0.00%
Expected volatility:	22.68%
Risk-free interest rate:	0.02%
Fair values:	$ 1.4572
Gain (loss) on extinguishment of warrant liabilities	(7,124)
Warrants Exercised on October 3, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:	Oct. 03, 2013
Market price of common stock:	$ 5.05
Exercise warrants:	35,000
Exercise price:	$ 3.5
Remaining contractual life (years):	29 days
Dividend yield:	0.00%
Expected volatility:	24.76%
Risk-free interest rate:	0.13%
Fair values:	$ 1.5485
Gain (loss) on extinguishment of warrant liabilities	(2,135)
Warrants Exercised on October 11, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:	Oct. 11, 2013
Market price of common stock:	$ 5.00
Exercise warrants:	96,652
Exercise price:	$ 3.5
Remaining contractual life (years):	18 days
Dividend yield:	0.00%
Expected volatility:	17.20%
Risk-free interest rate:	0.25%
Fair values:	$ 1.4956
Gain (loss) on extinguishment of warrant liabilities	(4,432)
Warrants Exercised on October 15, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:	Oct. 15, 2013
Market price of common stock:	$ 4.99
Exercise warrants:	12,500
Exercise price:	$ 3.5
Remaining contractual life (years):	14 days
Dividend yield:	0.00%
Expected volatility:	18.55%
Risk-free interest rate:	0.34%
Fair values:	$ 1.4899
Gain (loss) on extinguishment of warrant liabilities	(217)
Warrants Exercised on October 29, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:	Oct. 29, 2013
Market price of common stock:	$ 5.98
Exercise warrants:	15,000
Exercise price:	$ 3.5
Remaining contractual life (years):	0 years
Dividend yield:	0.00%
Expected volatility:	5.71%
Risk-free interest rate:	0.03%
Fair values:	$ 2.4788
Gain (loss) on extinguishment of warrant liabilities	(378)
Warrants Exercised on October 30, 2013
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Exercise date:	Oct. 30, 2013
Market price of common stock:	$ 5.92
Exercise warrants:	10,000
Exercise price:	$ 3.5
Remaining contractual life (years):	0 years
Dividend yield:	0.00%
Expected volatility:	0.00%
Risk-free interest rate:	0.00%
Fair values:	$ 2.4200
Gain (loss) on extinguishment of warrant liabilities	$ 2,397