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Derivative Instruments - Schedule of Location and Fair Value of Outstanding Commodity Derivative Instruments (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Derivatives, Fair Value [Line Items]    
Derivative asset, gross amounts recognized $ 3,168 $ 482
Derivative liability, gross amount recognized 29,874 81,002
Derivative asset, gross amounts offset (1,773) (120)
Derivative liability, gross amounts offset (9,759) (8,819)
Derivative asset, net asset 1,395 362
Derivative liability, net liability 20,115 72,183
Commodity derivative instruments [Member] | Current Assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, gross amounts recognized 971 482
Derivative asset, gross amounts offset (279) (120)
Derivative asset, net asset 692 362
Commodity derivative instruments [Member] | Noncurrent Assets [Member]    
Derivatives, Fair Value [Line Items]    
Derivative asset, gross amounts recognized 2,197  
Derivative asset, gross amounts offset (1,494)  
Derivative asset, net asset 703  
Commodity derivative instruments [Member] | Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability, gross amount recognized 24,590 66,838
Derivative liability, gross amounts offset (8,178) (6,369)
Derivative liability, net liability 16,412 60,469
Commodity derivative instruments [Member] | Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability, gross amount recognized 5,284 14,164
Derivative liability, gross amounts offset (1,581) (2,450)
Derivative liability, net liability $ 3,703 $ 11,714