XML 31 R36.htm IDEA: XBRL DOCUMENT v2.4.0.6
Financial Instruments (Details) (Fair Value, Measurements, Recurring [Member], USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets $ 1,591   
Total liability    (3,507)
Commodity Derivative Contracts [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets 1,591   
Total liability    (3,507)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets      
Total liability      
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commodity Derivative Contracts [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets      
Total liability      
Significant Other Observable Inputs (Level 2) [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets      
Total liability      
Significant Other Observable Inputs (Level 2) [Member] | Commodity Derivative Contracts [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets      
Total liability      
Significant Unobservable Inputs (Level 3) [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets 1,591   
Total liability    (3,507)
Significant Unobservable Inputs (Level 3) [Member] | Commodity Derivative Contracts [Member]
    
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis    
Total assets 1,591   
Total liability    $ (3,507)