Related Parties - Transportation Agreement with Monarch Oil Pipeline LLC (Details)
$ in Thousands
1 Months Ended 12 Months Ended
Sep. 01, 2013
May 07, 2013
May 31, 2015
USD ($)
Sep. 30, 2014
Dec. 31, 2016
USD ($)
MMBoe
director
Dec. 31, 2015
USD ($)
MMBoe
Dec. 31, 2014
USD ($)
MMBoe
Related Party Transactions              
Oil and gas sales         $ 124,877 $ 194,555 $ 378,401
Monarch Oil Pipeline LLC | Investee              
Related Party Transactions              
Term of Oil Gathering and Transportation Agreement (in years)       10 years      
Gathering fees         $ 2,700 $ 400  
Oil production transported (in MMBoe) | MMBoe         1.3 0.2  
Monarch Natural Gas, LLC | Investee              
Related Party Transactions              
Oil production transported (in MMBoe) | MMBoe           1.0 1.4
Oil and gas sales           $ 10,600 $ 37,000
Cash distributions associated with equity interests     $ 700        
Enable Midstream Partners LP              
Related Party Transactions              
Initial term of the agreement (in years) 10 years            
Metalmark | Beneficial owner              
Related Party Transactions              
Number of directors who are managing directors of the related party | director         2    
Metalmark | Monarch Natural Gas, LLC | Investee              
Related Party Transactions              
Metalmark Capital's ownership percentage in Monarch (as a percent)   81.00%          
Minimum | Metalmark | Beneficial owner              
Related Party Transactions              
Beneficial ownership interest (as a percent)         5.00%