Quarterly report pursuant to Section 13 or 15(d)

Divestitures - Additional Information (Details)

v3.5.0.2
Divestitures - Additional Information (Details)
 6 Months Ended
Oct. 15, 2015
USD ($)
a
$ / bbl
Jun. 30, 2016
USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]    
Gain (loss) on disposition of proved property $ 0  
Limit on percentage of reserves related to recognition of gain or loss 25.00%  
Crude Oil | Minimum    
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]    
Trading price per barrel | $ / bbl 70.00  
Crude Oil | Maximum    
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]    
Trading price per barrel | $ / bbl 90.00  
Ajax Resources, LLC    
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]    
Proceeds from sale of properties $ 370,900,000  
Acres of oil and gas property, net | a 25,800  
Agreement effective date Jan. 01, 2015  
Purchase price adjustment, net   $ 900,000
Ajax Resources, LLC | Minimum    
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]    
Overriding royalty interest 1.00%  
Ajax Resources, LLC | Maximum    
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]    
Overriding royalty interest 4.00%