Changes in Carrying Amount of Intangible Assets (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible asset carrying amount, beginning balance	$ 14,524,500
Amortization expense	514,556	513,867
Intangible asset carrying amount, ending balance	14,524,500
Intangible asset accumulated amortization, beginning balance	(5,444,105)
Intangible asset, accumulated amortization	(514,556)
Intangible asset accumulated amortization, ending balance	(5,958,661)
Intangible asset beginning balance, net	9,080,395
Amortization expense	(514,556)	(513,867)
Intangible asset ending balance, net	$ 8,565,839