XML 96 R57.htm IDEA: XBRL DOCUMENT v3.8.0.1
RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES - Part 3 (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]      
Accumulated other comprehensive loss $ (188,530) $ (154,350) $ (127,242)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net (35,013) (9,280)  
Cash Flow Hedging [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net (40,414) (35,752) 47,500
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net (90,586) 7,207 63,524
Commodity contracts | Cash Flow Hedging [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Unrealized Gain (Loss) On Cash Flow Hedges Net Of Tax Accumulated Other Comprehensive Income Loss (21,700)    
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months (19,300)    
Commodity Cash Flow Hedge Gain (Loss) To Be Reclassified After Next 12 Months Net (2,400)    
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net (40,577) (78,513) 70,065
Commodity contracts | Commodity sales revenues | Cash Flow Hedging [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net (69,561) 26,422 81,089
Interest Rate Contracts | Cash Flow Hedging [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of accumulated other comprehensive income (loss) attributable primarily to settled interest-rate swaps. (87,600)    
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net (14,000)    
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net 163 42,761 (22,565)
Interest Rate Contracts | Interest expense | Cash Flow Hedging [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net $ (21,025) $ (19,215) $ (17,565)