v3.3.1.900

Unaudited selected financial data (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2015 CAD / shares	Dec. 31, 2015 USD ($) $ / shares shares	Sep. 30, 2015 CAD / shares	Sep. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2015 CAD / shares	Jun. 30, 2015 USD ($) $ / shares shares	Mar. 31, 2015 CAD / shares	Mar. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Sep. 30, 2014 USD ($) $ / shares shares	Jun. 30, 2014 USD ($) $ / shares shares	Mar. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares
Unaudited selected quarterly financial data
Project revenue | $		$ 98.4		$ 107.4		$ 103.1		$ 111.3	$ 119.9	$ 121.6	$ 123.1	$ 125.3	$ 420.2	$ 489.9	$ 473.4
Project (loss) income | $		(104.3)		24.2		17.2		21.5	2.1	(64.7)	(2.0)	25.7	(41.4)	(38.9)	45.0
Loss (income) from continuing operations | $		(85.4)		(3.3)		(20.0)		24.6	(5.1)	(83.2)	(50.7)	(14.2)	(84.1)	(153.2)
(Loss) income from discontinued operations | $		(1.3)		(0.5)		33.6		(12.3)	(7.3)	(7.7)	(5.7)	(8.3)	19.5	(29.0)	(0.2)
Net loss attributable to Atlantic Power Corporation | $		$ (88.6)		$ (6.0)		$ 14.7		$ 17.5	$ (10.6)	$ (88.7)	$ (59.2)	$ (18.9)	$ (62.4)	$ (177.4)	$ (33.0)
Loss per share from continuing operations attributable to Atlantic Power Corporation (in dollars per share)		$ (0.71)		$ (0.05)		$ (0.18)		$ 0.18	$ (0.07)	$ (0.71)	$ (0.45)	$ (0.14)	$ (0.76)	$ (1.37)
Loss per share from discontinued operations (in dollars per share)		(0.01)				0.30		(0.04)	(0.02)	(0.02)	(0.04)	(0.02)	0.25	(0.10)
Net loss attributable to Atlantic Power Corporation		$ (0.72)		$ (0.05)		$ 0.12		$ 0.14	$ (0.09)	$ (0.73)	$ (0.49)	$ (0.16)	$ (0.51)	$ (1.47)
Weighted average number of common shares outstanding - basic | shares		122.1		122.1		121.9		121.5	121.0	120.7	120.6	120.3	121.9	120.7	119.9
Diluted (loss) income per share from continuing operations attributable to Atlantic Power Corporation		$ (0.71)		$ (0.05)		$ (0.18)		$ 0.18	$ (0.07)	$ (0.71)	$ (0.45)	$ (0.14)	$ (0.76)	$ (1.37)	$ (0.30)
Diluted (loss) income per share from discontinued operations		(0.01)				0.30		(0.04)	(0.02)	(0.02)	(0.04)	(0.02)	0.25	(0.10)	0.02
Diluted loss per share attributable to Atlantic Power Corporation		$ (0.72)		$ (0.05)		$ 0.12		$ 0.14	$ (0.09)	$ (0.73)	$ (0.49)	$ (0.16)	$ (0.51)	$ (1.47)	$ (0.28)
Weighted average number of common shares outstanding - diluted | shares		122.1		122.1		122.1		122.4	121.0	120.7	120.6	120.3	121.9	120.7	119.9
Dividend per common share (in dollars per share) | (per share)	CAD 0.03	$ 0.02	CAD 0.03	$ 0.02	CAD 0.03	$ 0.02	CAD 0.03	$ 0.03	$ 0.03	$ 0.07	$ 0.10	$ 0.10	$ 0.09	$ 0.29	$ 0.54

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