v2.4.0.8
Variable Interest Entities (Details) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Variable Interest Entities (Textuals)    
Power capacity under capital lease (MW) 236  
Capital Lease Agreement With Vie Remaining Term In Years 9  
Total payments over remaining terms of the agreement $ 226.0  
Total capacity and lease payments $ 37.8 $ 44.5