v2.4.0.8

Basic and diluted earnings (loss) per share (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2013
Basic and diluted earnings (loss) per share |
Schedule of diluted net income and potentially dilutive shares utilized in the per share calculation |
|  | Three months ended September 30, |  | Nine months ended September 30, |
--- | --- | --- | --- | --- | ---
|  | 2013 |  | 2012 |  | 2013 |  | 2012 |
Numerator: |  |  |  |  |  |  |  |  |  |  |  |  |
Loss from continuing operations attributable to Atlantic Power Corporation |  | $ | (40.9 | ) | $ | (26.5 | ) | $ | (31.8 | ) | $ | (103.7 | )
Income (loss) from discontinued operations, net of tax |  |  | (0.4 | ) |  | 19.0 |  |  | (6.1 | ) |  | 48.8 |
Net loss attributable to Atlantic Power Corporation |  | $ | (41.3 | ) | $ | (7.5 | ) | $ | (37.9 | ) | $ | (54.9 | )
Denominator: |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average basic shares outstanding |  |  | 120.0 |  |  | 119.0 |  |  | 119.8 |  |  | 115.4 |
Dilutive potential shares: |  |  |  |  |  |  |  |  |  |  |  |  |
Convertible debentures |  |  | 27.7 |  |  | 20.5 |  |  | 27.7 |  |  | 15.7 |
LTIP notional units |  |  | 0.8 |  |  | 0.5 |  |  | 0.7 |  |  | 0.5 |
Potentially dilutive shares |  |  | 148.5 |  |  | 140.0 |  |  | 148.2 |  |  | 131.6 |
Diluted loss per share from continuing operations attributable to Atlantic Power Corporation |  | $ | (0.34 | ) | $ | (0.22 | ) | $ | (0.27 | ) | $ | (0.90 | )
Diluted earnings (loss) per share from discontinued operations |  |  | (0.00 | ) |  | 0.16 |  |  | (0.05 | ) |  | 0.42 |
Diluted loss per share attributable to Atlantic Power Corporation |  | $ | (0.34 | ) | $ | (0.06 | ) | $ | (0.32 | ) | $ | (0.48 | )

X
- Details
Name: | us-gaap_EarningsPerShareAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration