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FINANCIAL INSTRUMENTS 2 (Details) (Derivatives Energy Related Assets [Member], Supplier Concentration Risk [Member], USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Derivatives Energy Related Assets [Member] | Supplier Concentration Risk [Member]
 
Concentration Risk [Line Items]  
Amount of derivatives - energy related assets with single retail counterparty $ 16.5
Percentage of derivatives - energy related assets with a single retail counterparty (in hundredths) 36.20%