Annual report pursuant to Section 13 and 15(d)

Derivative Instruments (Narrative) (Details)

v3.3.1.900
Derivative Instruments (Narrative) (Details)
12 Months Ended
Dec. 31, 2015
USD ($)
MMBTU / d
$ / MMBTU
Dec. 31, 2014
USD ($)
financial_institution
Dec. 31, 2013
USD ($)
Derivative [Line Items]      
Reduction to oil and condensate sales     $ 9,800,000
Number of financial institutions | financial_institution   4  
Gain on fair value hedge ineffectiveness, net $ (83,671,000) $ (121,148,000) 18,189,000
Gain on fair value hedge ineffectiveness     9,100,000
Loss related to amortization of OCI from hedging activity     $ 9,100,000
Production delivered under fixed price swaps, percentage 46.00%    
January 2017 - December 2017      
Derivative [Line Items]      
Daily Volume (MMBtu/day) | MMBTU / d 30,000    
Weighted Average Price | $ / MMBTU 3.33    
January 2017 - December 2017 | Short      
Derivative [Line Items]      
Daily Volume (MMBtu/day) | MMBTU / d 30,000    
Weighted Average Price | $ / MMBTU 3.33    
Swap      
Derivative [Line Items]      
AOCI before Tax, Attributable to Parent $ 0    
Swaption      
Derivative [Line Items]      
AOCI before Tax, Attributable to Parent 0    
Basis Swap      
Derivative [Line Items]      
AOCI before Tax, Attributable to Parent $ 0