Derivative and Hedging Financial Instruments - Summary of Realized and Unrealized Gains and Losses Related to Derivative Instrument (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Gain (Loss) on Investments [Abstract]
Realized gains (loss) on commodity derivative	$ 2,030,176	$ (260,542)
Change in fair value of derivatives	5,345,004	(305,650)
Total realized and unrealized gains/(losses) recorded	$ 7,375,180
Total realized and unrealized gains/(losses) recorded		$ (566,192)