Derivative and Hedging Financial Instruments - Summary of Fair Value of Derivatives (Detail) - USD ($)	Jun. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Commodity derivative, Current assets	$ 3,577,996	$ 5,420,309
Commodity derivative, Noncurrent assets		2,809,847
Derivative assets fair value	3,577,996	8,230,156
Commodity derivative, Noncurrent liabilities	1,345,504	716,488
Derivative liabilities fair value	1,345,504	716,488
Commodity Contract [Member]
Derivative [Line Items]
Commodity derivative, Current assets	3,577,996	5,420,309
Commodity derivative, Noncurrent assets		2,809,847
Derivative assets fair value	3,577,996	8,230,156
Commodity derivative, Current liabilities	0	0
Commodity derivative, Noncurrent liabilities	1,345,504	716,488
Derivative liabilities fair value	$ 1,345,504	$ 716,488