Derivative and Hedging Financial Instruments - Summary of Fair Value of Derivatives (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Commodity derivative, Current assets	$ 3,160,081	$ 5,420,309
Commodity derivative, Noncurrent assets	1,376,585	2,809,847
Derivative assets fair value	4,536,666	8,230,156
Commodity derivative, Current liabilities	226,633
Commodity derivative, Noncurrent liabilities	1,264,412	716,488
Derivative liabilities fair value	1,491,045	716,488
Commodity Contract [Member]
Derivative [Line Items]
Commodity derivative, Current assets	3,160,081	5,420,309
Commodity derivative, Noncurrent assets	1,376,585	2,809,847
Derivative assets fair value	4,536,666	8,230,156
Commodity derivative, Current liabilities	226,633
Commodity derivative, Noncurrent liabilities	1,264,412	716,488
Derivative liabilities fair value	$ 1,491,045	$ 716,488