v2.4.0.6
Segment and geographic information (Details 2) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Revenue and Assets                      
Project Revenue $ 113,952 $ 106,305 $ 101,421 $ 118,699 $ 79,158 $ 5,035 $ 5,107 $ 4,595 $ 440,377 $ 93,895 $ 1,051
Property, plant, and equipment, net 2,055,510       1,388,254       2,055,510 1,388,254  
United States
                     
Revenue and Assets                      
Project Revenue                 227,212 58,109 1,051
Property, plant, and equipment, net 1,504,809       816,744       1,504,809 816,744  
Canada
                     
Revenue and Assets                      
Project Revenue                 213,165 35,786  
Property, plant, and equipment, net $ 550,701       $ 571,510       $ 550,701 $ 571,510