v2.4.0.8
Basis of presentation and summary of significant accounting policies (Details)
1 Months Ended 6 Months Ended
Apr. 30, 2013
item
Jun. 30, 2013
MW
state
province
project
Jun. 30, 2013
Gregory
Dec. 31, 2012
Delta-Person
Basis of presentation and summary of significant accounting policies        
Percentage of ownership interest     17.10% 40.00%
Gross generating capacity of project (in MW)   3,018    
Ownership interest in operational power generation projects (in MW)   2,098    
Number of operational power generation projects   29    
Number of states in which power generation projects operate   11    
Number of provinces in which power generation projects operate   2    
Power of project that achieved commercial operations 53      
Number of projects Which are wholly owned subsidiaries   23