CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Project revenue:
Energy sales	$ 40.0	$ 45.1	$ 77.1	$ 97.6
Energy capacity revenue	28.3	37.3	47.8	69.2
Other	55.7	15.8	97.5	37.8
Total project revenue	124.0	98.2	222.4	204.6
Project expenses:
Fuel	24.0	35.1	52.9	74.0
Operations and maintenance	23.3	30.0	43.6	51.2
Depreciation and amortization	29.5	25.5	59.0	50.3
Total project costs	76.8	90.6	155.5	175.5
Project other income:
Change in fair value of derivative instruments (Notes 5 and 6)	(2.7)	12.2	(3.9)	11.0
Equity in (loss) earnings of unconsolidated affiliates (Note 3)	(54.4)	7.6	(45.4)	18.3
Interest expense, net	(2.2)	(2.4)	(4.4)	(4.5)
Other income, net		0.2
Total project other income (expense)	(59.3)	17.6	(53.7)	24.8
Project (loss) income	(12.1)	25.2	13.2	53.9
Administrative and other expenses:
Administration	5.7	5.8	12.1	11.9
Interest expense, net	18.4	51.2	35.7	67.8
Foreign exchange loss	5.9	2.6	8.3	22.5
Other income (expense), net		0.3		(2.2)
Total administrative and other expenses (income)	30.0	59.9	56.1	100.0
Loss from operations before income taxes	(42.1)	(34.7)	(42.9)	(46.1)
Income tax benefit (Note 7)	(22.3)	(18.4)	(22.6)	(16.8)
Net loss	(19.8)	(16.3)	(20.3)	(29.3)
Net income attributable to preferred shares dividends of a subsidiary company	2.1	2.2	4.3	4.2
Net loss attributable to Atlantic Power Corporation	$ (21.9)	$ (18.5)	$ (24.6)	$ (33.5)
Net loss per share attributable to Atlantic Power Corporation shareholders: (Note 9)
Basic	$ (0.19)	$ (0.15)	$ (0.21)	$ (0.28)
Diluted	$ (0.19)	$ (0.15)	$ (0.21)	$ (0.28)
Weighted average number of common shares outstanding: (Note 9)
Basic (in shares)	115.2	121.6	115.0	121.8
Diluted (in shares)	115.2	121.6	115.0	121.8