Annual report pursuant to Section 13 and 15(d)

Derivative Instruments - Gain (Loss) on Derivative Instruments (Details)

v3.6.0.2
Derivative Instruments - Gain (Loss) on Derivative Instruments (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Derivative [Line Items]        
Gain due to changes in fair value of derivative instruments $ (174,506) $ 203,513   $ 109,299
Natural gas derivatives        
Derivative [Line Items]        
Gain due to changes in fair value of derivative instruments (165,933) 182,993 $ 103,128  
Oil derivatives        
Derivative [Line Items]        
Gain due to changes in fair value of derivative instruments (5,387) 19,201 6,171  
Natural gas liquids derivatives        
Derivative [Line Items]        
Gain due to changes in fair value of derivative instruments $ (3,186) $ 1,319 $ 0