Derivative and Hedging Financial Instruments - Summary of Realized and Unrealized Gains and Losses Related to Derivative Instrument (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Total realized and unrealized gains/(losses) recorded	$ 12,356,168	$ 8,588,535
Commodity Contract [Member]
Derivative [Line Items]
Realized gains on commodity derivative	15,756,161	949,094
Change in fair value of commodity derivative	$ (3,399,993)	$ 7,639,441