v3.3.1.900
Summary of significant accounting policies (Tables)
12 Months Ended
Dec. 31, 2015
Nature of business  
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

 

Natural gas swaps

 

Changes in fair value of derivative instrument

 

Fuel expense

 

Fuel 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 (gain) loss