Derivative and Hedging Financial Instruments - Summary of Realized and Unrealized Gains and Losses Related to Derivative Instrument (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative [Line Items]
Total contract gains recorded	$ 2,100,443	$ 2,922,063	$ 703,371	$ 9,770,324
Commodity Contract [Member]
Derivative [Line Items]
Cash settlements on commodity derivatives	463,299	2,108,934	2,992,891	14,238,371
Change in fair value of commodity derivatives	$ 1,637,144	$ 813,129	$ (2,289,520)	$ (4,468,047)