v2.4.0.6

Summary of significant accounting policies (Tables) | 12 Months Ended
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Dec. 31, 2012
Summary of significant accounting policies |
Summary of derivative financial instruments that are not designated as hedges for accounting purposes and the accounting treatment in the consolidated statements of operations of the changes in fair value and cash settlements of such derivative financial instrument |
Derivative financial instrument |  | Classification of changes in fair value |  | Classification of cash settlements
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Natural gas swaps |  | Changes in fair value of derivative instrument |  | Fuel expense
Gas purchase agreements |  | Changes in fair value of derivative instrument |  | Fuel expense
Interest rate swaps |  | Changes in fair value of derivative instrument |  | Interest expense
Foreign currency forward contract |  | Foreign exchange (gain) loss |  | Foreign exchange loss (gain)

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- Definition Tabular disclosure for other derivative instruments that are not designated as hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position. + References No definition available. + Details
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- Details
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