Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Oil production revenue	$ 261,060	$ 167,624
Gas production revenue	79,109	101,151
NGL production revenue	42,717	64,423
Total oil, gas, and NGL production revenue	382,886	333,198
Permian
Segment Reporting Information [Line Items]
Oil production revenue	205,794	81,499
Gas production revenue	24,876	11,309
NGL production revenue	124	147
Total oil, gas, and NGL production revenue	230,794	92,955
South Texas & Gulf Coast
Segment Reporting Information [Line Items]
Oil production revenue	19,583	38,864
Gas production revenue	52,733	88,201
NGL production revenue	41,770	63,357
Total oil, gas, and NGL production revenue	114,086	190,422
Rocky Mountain
Segment Reporting Information [Line Items]
Oil production revenue	35,683	47,261
Gas production revenue	1,500	1,641
NGL production revenue	823	919
Total oil, gas, and NGL production revenue	$ 38,006	$ 49,821
Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Relative percentage	100.00%	100.00%
Sales Revenue, Net | Geographic Concentration Risk | Permian
Segment Reporting Information [Line Items]
Relative percentage	60.00%	28.00%
Sales Revenue, Net | Geographic Concentration Risk | South Texas & Gulf Coast
Segment Reporting Information [Line Items]
Relative percentage	30.00%	57.00%
Sales Revenue, Net | Geographic Concentration Risk | Rocky Mountain
Segment Reporting Information [Line Items]
Relative percentage	10.00%	15.00%