Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	$ 13,780	$ (2,913)	$ 32,285	$ (4,756)
Unrealized loss on derivatives	(23,532)	(5,234)	(32,090)	(8,342)
Total	(9,752)	(8,147)	195	(13,098)
Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	13,780	(2,913)	32,285	(4,756)
Unrealized loss on derivatives	(23,532)	(5,234)	(32,090)	(8,342)
Oil | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	10,524	(2,764)	24,957	(3,706)
Unrealized loss on derivatives	(19,880)	(5,701)	(26,345)	(7,751)
Natural Gas | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	2,716	(187)	6,315	(776)
Unrealized loss on derivatives	(3,281)	698	(4,843)	(569)
NGL | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	540	38	1,013	(274)
Unrealized loss on derivatives	$ (371)	$ (231)	$ (902)	$ (22)