Annual report pursuant to Section 13 and 15(d)

Supplemental Information on Oil and Natural Gas Properties (unaudited) (Capitalized Costs Relating to Oil and Natural Gas Activities - Additional Information) (Details)

v3.6.0.2
Supplemental Information on Oil and Natural Gas Properties (unaudited) (Capitalized Costs Relating to Oil and Natural Gas Activities - Additional Information) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Reserve Quantities [Line Items]        
Unevaluated property balance $ 668,721 $ 132,181 $ 142,525 $ 43,222
Monarch Operating Area [Member]        
Reserve Quantities [Line Items]        
Unevaluated property balance 123,345      
WildHorse Operating Area [Member]        
Reserve Quantities [Line Items]        
Unevaluated property balance 521,520      
Ranger Operating Area [Member]        
Reserve Quantities [Line Items]        
Unevaluated property balance $ 23,856      
Minimum [Member]        
Reserve Quantities [Line Items]        
Unevaluated property costs expected evaluation period range 10 years      
Maximum [Member]        
Reserve Quantities [Line Items]        
Unevaluated property costs expected evaluation period range 15 years