Basic and diluted earnings (loss) per share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
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| Numerator: | |||||||||||
| Loss from continuing operations attributable to Atlantic Power Corporation | $ (92.9) | $ (164.8) | $ (36.2) | ||||||||
| Income (loss) from discontinued operations, net of tax | 30.5 | (12.6) | 3.2 | ||||||||
| 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) |
| Denominator: | |||||||||||
| Weighted average basic shares outstanding | 122.1 | 122.1 | 121.9 | 121.5 | 121.0 | 120.7 | 120.6 | 120.3 | 121.9 | 120.7 | 119.9 |
| Dilutive potential shares: | |||||||||||
| Convertible debentures (in shares) | 22.7 | 27.7 | 27.7 | ||||||||
| LTIP notional units (in shares) | 0.2 | 0.3 | 0.7 | ||||||||
| Potentially dilutive shares | 144.8 | 148.7 | 148.3 | ||||||||
| Diluted loss 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 earnings (loss) 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) |
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- Definition The average number of shares or units issued and outstanding including net loss that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. No definition available.
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- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Per diluted share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- References No definition available.
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- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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