v2.4.0.6
Assets held for sale (Details) (USD $)
 3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Dec. 31, 2012
Held for Sale Business      
Reserve related to sale of discontinued operations included in liabilities associated with assets held for sale $ 27,500,000    
Reserve related to sale of discontinued operations 27,500,000    
Period of project disposal 12 months    
Revenue 63,200,000 49,000,000  
Income from operations of discontinued businesses 1,300,000 12,200,000  
Income tax expense 400,000 600,000  
Income from operations of discontinued businesses, net of tax 900,000 11,600,000  
Current assets:      
Cash and cash equivalents 5,000,000   6,500,000
Restricted cash 16,500,000   12,600,000
Accounts receivable 22,600,000   21,900,000
Other current assets 5,600,000   6,300,000
Total current assets 49,700,000   47,300,000
Non-current assets:      
Property, plant, & equipment 110,100,000   111,900,000
Transmission system rights 170,500,000   172,400,000
Goodwill 8,900,000   8,900,000
Other assets 7,600,000   10,900,000
Assets held for sale 346,800,000   351,400,000
Current liabilities:      
Accounts payable and other accrued liabilities 15,500,000   16,500,000
Current portion of long-term debt 13,000,000   14,300,000
Current portion of derivative instruments liability 11,500,000   20,000,000
Other liabilities 27,800,000   500,000
Total current liabilities 205,300,000   189,000,000
Long-term liabilities      
Long-term debt 137,500,000   137,700,000
Liabilities held for sale $ 205,300,000   $ 189,000,000