Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	$ 485	$ 885	$ (1,176)	$ 10,413
Unrealized (loss) gain on derivatives	(12,372)	3,203	21,449	(30,261)
Total	(11,887)	4,088	20,273	(19,848)
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	485	885	(1,176)	10,413
Unrealized (loss) gain on derivatives	(12,372)	3,203	21,449	(30,261)
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	485	837	(568)	6,861
Unrealized (loss) gain on derivatives	(12,479)	2,007	15,949	(24,967)
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	0	48	(608)	3,552
Unrealized (loss) gain on derivatives	115	1,196	5,508	(5,294)
Natural Gas Liquids [Member] | Revenues
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Unrealized (loss) gain on derivatives	$ (8)	$ 0	$ (8)	$ 0