v2.4.0.8
Guarantees and condensed consolidating financial information (Details 2) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2013
Dec. 31, 2012
Sep. 30, 2012
Dec. 31, 2011
Current assets:        
Cash and cash equivalents $ 170.7 $ 60.2 $ 42.9 $ 60.7
Restricted cash 119.8 28.6    
Accounts receivable 63.3 58.5    
Prepayments, supplies, and other current assets 34.3      
Total current assets 388.1 561.7    
Property, plant, and equipment, net 1,873.9 2,055.5    
Equity investments in unconsolidated affiliates 404.5 428.7    
Other intangible assets, net 471.1 524.9    
Goodwill 296.3 334.7    
Other assets 62.8      
Total assets 3,496.7 4,002.7 3,644.0  
Current liabilities:        
Accounts payable and accrued liabilities 90.1      
Revolving credit facility   67.0    
Current portion of long-term debt 206.7 121.2    
Other current liabilities 42.9      
Total current liabilities 339.7 535.5    
Long-term debt 1,274.1 1,459.1    
Convertible debentures 414.1 424.2    
Other non-current liabilities 347.8      
Total liabilities 2,375.7 2,816.3    
Equity        
Preferred shares issued by a subsidiary company 221.3 221.3    
Common shares 1,285.7 1,285.5    
Accumulated other comprehensive income (loss) (8.7) 9.4    
Retained deficit (649.6) (565.2)    
Total Atlantic Power Corporation shareholders' equity 848.7 951.0    
Noncontrolling interest 272.3 235.4    
Total equity 1,121.0 1,186.4 1,052.8 1,115.8
Total liabilities and equity 3,496.7 4,002.7    
Eliminations
        
Current assets:        
Accounts receivable (116.3)      
Prepayments, supplies, and other current assets (1.0)      
Total current assets (117.3)      
Property, plant, and equipment, net (1.3)      
Equity investments in unconsolidated affiliates (4,313.1)      
Other assets (845.2)      
Total assets (5,276.9)      
Current liabilities:        
Accounts payable and accrued liabilities (116.3)      
Other current liabilities (1.0)      
Total current liabilities (117.3)      
Other non-current liabilities (845.2)      
Total liabilities (962.5)      
Equity        
Preferred shares issued by a subsidiary company (10.8)      
Common shares (4,514.7)      
Retained deficit 211.1      
Total Atlantic Power Corporation shareholders' equity (4,314.4)      
Total equity (4,314.4)      
Total liabilities and equity (5,276.9)      
Guarantor Subsidiaries | Reportable legal entities
        
Current assets:        
Cash and cash equivalents 163.5 49.5    
Restricted cash 119.8      
Accounts receivable 165.9      
Prepayments, supplies, and other current assets 32.2      
Total current assets 481.4      
Property, plant, and equipment, net 1,702.7      
Equity investments in unconsolidated affiliates 3,753.9      
Other intangible assets, net 321.5      
Goodwill 238.1      
Other assets 473.7      
Total assets 6,971.3      
Current liabilities:        
Accounts payable and accrued liabilities 118.6      
Current portion of long-term debt 16.7      
Other current liabilities 40.0      
Total current liabilities 175.3      
Long-term debt 814.1      
Other non-current liabilities 1,184.0      
Total liabilities 2,173.4      
Equity        
Preferred shares issued by a subsidiary company 232.1      
Common shares 4,323.5      
Accumulated other comprehensive income (loss) (8.7)      
Retained deficit (21.3)      
Total Atlantic Power Corporation shareholders' equity 4,525.6      
Noncontrolling interest 272.3      
Total equity 4,797.9      
Total liabilities and equity 6,971.3      
Curtis Palmer | Reportable legal entities
        
Current assets:        
Accounts receivable 10.9      
Prepayments, supplies, and other current assets 2.3      
Total current assets 13.2      
Property, plant, and equipment, net 172.5      
Other intangible assets, net 149.6      
Goodwill 58.2      
Total assets 393.5      
Current liabilities:        
Accounts payable and accrued liabilities 3.9      
Current portion of long-term debt 190.0      
Total current liabilities 193.9      
Other non-current liabilities 8.5      
Total liabilities 202.4      
Equity        
Common shares 191.1      
Total Atlantic Power Corporation shareholders' equity 191.1      
Total equity 191.1      
Total liabilities and equity 393.5      
Atlantic Power | Reportable legal entities
        
Current assets:        
Cash and cash equivalents 7.2 16.9    
Accounts receivable 2.8      
Prepayments, supplies, and other current assets 0.8      
Total current assets 10.8      
Equity investments in unconsolidated affiliates 963.7      
Other assets 434.3      
Total assets 1,408.8      
Current liabilities:        
Accounts payable and accrued liabilities 83.9      
Other current liabilities 3.9      
Total current liabilities 87.8      
Long-term debt 460.0      
Convertible debentures 414.1      
Other non-current liabilities 0.5      
Total liabilities 962.4      
Equity        
Common shares 1,285.8      
Retained deficit (839.4)      
Total Atlantic Power Corporation shareholders' equity 446.4      
Total equity 446.4      
Total liabilities and equity $ 1,408.8