Derivative Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Summary of location and aggregate fair value of all derivative financial instruments recorded in the consolidated statements of operations
Realized gain (loss) on derivatives	$ 5,424	$ 485	$ (1,322)	$ (1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
Total	(15,913)	(11,887)	(10,814)	20,273
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	5,424	485	(1,322)	(1,176)
Unrealized (loss) gain on derivatives	(21,337)	(12,372)	(9,492)	21,449
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	5,424	485	(1,373)	(568)
Unrealized (loss) gain on derivatives	(21,240)	(12,479)	(8,284)	15,949
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	0	51	(608)
Unrealized (loss) gain on derivatives	(97)	115	(1,208)	5,508
NGL | 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	$ 0	$ (8)	$ 0	$ (8)