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Unaudited Supplemental Oil and Gas Information - Schedule of Proved Oil and Gas Reserves and Changes in Net Proved Reserves (Details) - bbl
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Oil (bbls) [Member]      
Reserve quantities, beginning of year 657,280 1,615,180 4,119,736
Revisions of previous estimates 302,530 (795,459) (2,377,364)
Discoveries and extensions 22,801 23,841 94,458
Sale of minerals in place (194,667) (53,853)
Production (111,914) (132,429) (221,650)
Reserve quantities, end of year 676,030 657,280 1,615,180
Proved developed reserves, end of year 676,030 657,280 1,248,750
Natural Gas (mcfe) [Member]      
Reserve quantities, beginning of year [1],[2] 1,379,163    
Revisions of previous estimates [2] 55,072    
Discoveries and extensions [2] 21,787    
Sale of minerals in place [2] (118,944)    
Production [2] (448,571)    
Reserve quantities, end of year [2] 888,507 1,379,163 [1]  
Proved developed reserves, end of year [2] 888,507    
Natural Gas (mcfe) [Member]      
Reserve quantities, beginning of year [2] 1,379,163 [1] 2,477,930 3,211,245
Revisions of previous estimates [2]   (584,494) (206,912)
Discoveries and extensions [2]   20,336 27,105
Sale of minerals in place [2]   (57,258)
Production [2]   (477,351) (553,505)
Reserve quantities, end of year [2]   1,379,163 [1] 2,477,930
Proved developed reserves, end of year   1,379,163 [1] 2,068,190 [2]
[1] Consists of the weighted average price for natural gas in mcf plus NGL’s converted to mcf using a factor of 6 mcf for each barrel of NGL.
[2] Mcf equivalents (Mcfe) consist of natural gas reserves in mcf plus NGLs converted to mcf using a factor of 6 mcf for each barrel of NGL.