XML 77 R59.htm IDEA: XBRL DOCUMENT v3.6.0.2
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Before Tax Effect of Derivative Instruments in Statement of Operations (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]      
Increase in oil revenue owing to effective hedging contracts $ 23,747 $ 135,617 $ 7,929
Increase (decrease) in gas revenue owing to effective hedging contracts 11,710 14,338 (7,403)
Designated as Hedging Instrument | Cash Flow Hedging      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives (1,648) 52,630 136,097
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion) 35,457 149,955 526
Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion) (810) 2,713 5,721
Designated as Hedging Instrument | Cash Flow Hedging | Operating revenue - oil/natural gas production      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion) 35,457 149,955 526
Designated as Hedging Instrument | Cash Flow Hedging | Derivative income (expense), net      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion) (810) 2,713 5,721
Designated as Hedging Instrument | Cash Flow Hedging | Commodity contracts      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives $ (1,648) $ 52,630 $ 136,097