XML 39 R79.htm IDEA: XBRL DOCUMENT v2.4.0.6
Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (Fair Value, Measurements, Recurring, USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value $ 132,934 $ 65,531
Liabilities measured at fair value 74,647 165,130
Restricted deposits
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 27,947 27,912
Commodity derivatives contracts
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 94,639 30,481
Liabilities measured at fair value 72,252 154,682
Investments
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 10,348 7,138
Interest rate swap
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Liabilities measured at fair value 2,395 10,448
Fair Value Measurements Level 1
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 38,295 35,050
Liabilities measured at fair value 0 0
Fair Value Measurements Level 1 | Restricted deposits
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 27,947 27,912
Fair Value Measurements Level 1 | Commodity derivatives contracts
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 0
Liabilities measured at fair value 0 0
Fair Value Measurements Level 1 | Investments
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 10,348 7,138
Fair Value Measurements Level 1 | Interest rate swap
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Liabilities measured at fair value 0 0
Fair Value Measurements Level 2
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 130,220 62,746
Liabilities measured at fair value 109,716 193,142
Fair Value Measurements Level 2 | Restricted deposits
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 0
Fair Value Measurements Level 2 | Commodity derivatives contracts
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 130,220 62,746
Liabilities measured at fair value 107,321 182,694
Fair Value Measurements Level 2 | Investments
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 0
Fair Value Measurements Level 2 | Interest rate swap
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Liabilities measured at fair value 2,395 10,448
Fair Value Measurements Level 3
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 183 397
Liabilities measured at fair value 695 4,650
Fair Value Measurements Level 3 | Restricted deposits
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 0
Fair Value Measurements Level 3 | Commodity derivatives contracts
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 183 397
Liabilities measured at fair value 695 4,650
Fair Value Measurements Level 3 | Investments
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 0
Fair Value Measurements Level 3 | Interest rate swap
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Liabilities measured at fair value 0 0
Netting
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value (35,764) [1] (32,662) [1]
Liabilities measured at fair value (35,764) [1] (32,662) [1]
Netting | Restricted deposits
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 [1] 0 [1]
Netting | Commodity derivatives contracts
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value (35,764) [1] (32,662) [1]
Liabilities measured at fair value (35,764) [1] (32,662) [1]
Netting | Investments
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Assets measured at fair value 0 [1] 0 [1]
Netting | Interest rate swap
    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Liabilities measured at fair value $ 0 [1] $ 0 [1]
[1] Represents the impact of netting assets and liabilities with counterparties with which the right of offset exists.