Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain on derivatives	$ 2,465	$ 13,780	$ 9,528	$ 32,285
Unrealized loss on derivatives	(26,625)	(23,532)	(33,464)	(32,090)
Total	(24,160)	(9,752)	(23,936)	195
Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain on derivatives	2,465	13,780	9,528	32,285
Unrealized loss on derivatives	(26,625)	(23,532)	(33,464)	(32,090)
Oil | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain on derivatives	561	10,524	6,024	24,957
Unrealized loss on derivatives	(19,319)	(19,880)	(26,974)	(26,345)
Natural Gas | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain on derivatives	1,904	2,716	3,504	6,315
Unrealized loss on derivatives	(7,306)	(3,281)	(6,490)	(4,843)
Natural Gas Liquids | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain on derivatives	0	540	0	1,013
Unrealized loss on derivatives	$ 0	$ (371)	$ 0	$ (902)