v2.4.0.8
Guarantees and condensed consolidating financial information (Details 3) (USD $)
 3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Project revenue:        
Total project revenue $ 141,800,000 $ 106,300,000 $ 421,000,000 $ 326,400,000
Project expenses:        
Fuel 47,200,000 40,100,000 148,800,000 123,600,000
Project operations and maintenance 38,000,000 26,500,000 112,300,000 88,000,000
Development 1,400,000   4,900,000  
Depreciation and amortization 42,200,000 30,600,000 125,700,000 87,300,000
Total project expenses 128,800,000 97,200,000 391,700,000 298,900,000
Project other income (expense):        
Change in fair value of derivative instruments (3,500,000) 10,700,000 33,400,000 (51,300,000)
Equity in earnings of unconsolidated affiliates 39,100,000 4,000,000 55,000,000 12,400,000
Interest expense, net (9,000,000) (4,100,000) (25,700,000) (12,300,000)
Other (34,800,000)   (34,700,000)  
Total project other income (expense) (8,200,000) 10,600,000 28,000,000 (51,200,000)
Project income 4,800,000 19,700,000 57,300,000 (23,700,000)
Administrative and other expenses (income):        
Administration expense 8,400,000 6,300,000 28,500,000 22,000,000
Interest, net 27,500,000 25,800,000 78,700,000 69,300,000
Foreign exchange gain (loss) 9,100,000 7,700,000 (12,900,000) 4,400,000
Other income   300,000 (9,500,000) (5,700,000)
Total administrative and other expenses (income) 45,000,000 40,100,000 84,800,000 90,000,000
Loss from continuing operations before income taxes (40,200,000) (20,400,000) (27,500,000) (113,700,000)
Income tax benefit   3,100,000 (1,900,000) (19,100,000)
Net loss from continuing operations (40,200,000) (23,500,000) (25,600,000) (94,600,000)
Net loss from discontinued operations (400,000) 19,000,000 (6,100,000) 48,800,000
Net loss (40,600,000) (4,500,000) (31,700,000) (45,800,000)
Net income (loss) attributable to noncontrolling interest (2,500,000) (400,000) (3,300,000) (700,000)
Net loss attributable to Atlantic Power Corporation (41,300,000) (7,500,000) (37,900,000) (54,900,000)
Eliminations
        
Project revenue:        
Total project revenue (200,000)   (500,000)  
Project expenses:        
Project operations and maintenance (100,000)   (400,000)  
Total project expenses (100,000)   (400,000)  
Project other income (expense):        
Project income (100,000)   (100,000)  
Administrative and other expenses (income):        
Loss from continuing operations before income taxes (100,000)   (100,000)  
Net loss from continuing operations (100,000)   (100,000)  
Net loss (100,000)   (100,000)  
Net income (loss) attributable to noncontrolling interest 3,200,000   9,500,000  
Net loss attributable to Atlantic Power Corporation (3,300,000)   (9,600,000)  
Guarantor Subsidiaries | Reportable legal entities
        
Project revenue:        
Total project revenue 134,200,000   394,100,000  
Project expenses:        
Fuel 47,200,000   148,800,000  
Project operations and maintenance 36,800,000   110,000,000  
Development 1,400,000   4,900,000  
Depreciation and amortization 38,400,000   114,200,000  
Total project expenses 123,800,000   377,900,000  
Project other income (expense):        
Change in fair value of derivative instruments (3,500,000)   33,400,000  
Equity in earnings of unconsolidated affiliates 39,100,000   55,000,000  
Interest expense, net (6,300,000)   (17,400,000)  
Other (34,800,000)   (35,000,000)  
Total project other income (expense) (5,500,000)   36,000,000  
Project income 4,900,000   52,200,000  
Administrative and other expenses (income):        
Administration expense 4,900,000   15,300,000  
Interest, net 18,900,000   57,100,000  
Foreign exchange gain (loss) 4,100,000   (3,900,000)  
Other income     (9,500,000)  
Total administrative and other expenses (income) 27,900,000   59,000,000  
Loss from continuing operations before income taxes (23,000,000)   (6,800,000)  
Income tax benefit     (1,900,000)  
Net loss from continuing operations (23,000,000)   (4,900,000)  
Net loss from discontinued operations (400,000)   (6,100,000)  
Net loss (23,400,000)   (11,000,000)  
Net income (loss) attributable to noncontrolling interest (2,500,000)   (3,300,000)  
Net loss attributable to Atlantic Power Corporation (20,900,000)   (7,700,000)  
Curtis Palmer | Reportable legal entities
        
Project revenue:        
Total project revenue 7,800,000   27,400,000  
Project expenses:        
Project operations and maintenance 1,300,000   2,200,000  
Depreciation and amortization 3,800,000   11,500,000  
Total project expenses 5,100,000   13,700,000  
Project other income (expense):        
Interest expense, net (2,700,000)   (8,300,000)  
Total project other income (expense) (2,700,000)   (8,300,000)  
Project income     5,400,000  
Administrative and other expenses (income):        
Loss from continuing operations before income taxes     5,400,000  
Net loss from continuing operations     5,400,000  
Net loss     5,400,000  
Net loss attributable to Atlantic Power Corporation     5,400,000  
Atlantic Power | Reportable legal entities
        
Project expenses:        
Project operations and maintenance     500,000  
Total project expenses     500,000  
Project other income (expense):        
Other     300,000  
Total project other income (expense)     300,000  
Project income     (200,000)  
Administrative and other expenses (income):        
Administration expense 3,500,000   13,200,000  
Interest, net 8,600,000   21,600,000  
Foreign exchange gain (loss) 5,000,000   (9,000,000)  
Total administrative and other expenses (income) 17,100,000   25,800,000  
Loss from continuing operations before income taxes (17,100,000)   (26,000,000)  
Net loss from continuing operations (17,100,000)   (26,000,000)  
Net loss (17,100,000)   (26,000,000)  
Net loss attributable to Atlantic Power Corporation $ (17,100,000)   $ (26,000,000)