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Cumulative Preferred Stock (Details) - CAD CAD / shares in Units, CAD in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Aug. 17, 2015
Class of Stock [Line Items] |  |  |
Preferred Stock, Shares Outstanding | 29,000,000 | 29,000,000 |
Proceeds From Issuance Of Preferred Stock And Preference Stock Net | CAD 709.0 | CAD 709.0 |
Series A Preferred Stock [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | CAD 0.6388 |  |
Preferred Stock, Shares Outstanding | 3,864,636 |  | 6,000,000
Series A Preferred Stock [Member] | TECO Energy Inc [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | CAD 0.6388 |  |
Preferred Stock, Redemption Price Per Share | CAD 25 |  |
Preferred Stock, Shares Outstanding | 3,864,636 | 3,864,636 |
Proceeds From Issuance Of Preferred Stock And Preference Stock Net | CAD 95.0 | CAD 95.0 |
Series B Preferred Stock [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | CAD 0.5724 |  |
Preferred Stock, Shares Outstanding | 2,135,364 |  |
Series B Preferred Stock [Member] | TECO Energy Inc [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Redemption Price Per Share | CAD 25 |  |
Preferred Stock, Shares Outstanding | 2,135,364 | 2,135,364 |
Proceeds From Issuance Of Preferred Stock And Preference Stock Net | CAD 52.0 | CAD 52.0 |
Dividends Payable Nature | Floating |  |
Series C Preferred Stock [Member] | TECO Energy Inc [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | CAD 1.025 |  |
Preferred Stock, Redemption Price Per Share | CAD 25 |  |
Preferred Stock, Shares Outstanding | 10,000,000 | 10,000,000 |
Proceeds From Issuance Of Preferred Stock And Preference Stock Net | CAD 245.0 | CAD 245.0 |
Series E Preferred Stock [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | CAD 1.125 |  |
Series E Preferred Stock [Member] | TECO Energy Inc [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | 1.125 |  |
Preferred Stock, Redemption Price Per Share | CAD 26 |  |
Preferred Stock, Shares Outstanding | 5,000,000 | 5,000,000 |
Proceeds From Issuance Of Preferred Stock And Preference Stock Net | CAD 122.0 | CAD 122.0 |
Series F Preferred Stock [Member] | TECO Energy Inc [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred Stock, Dividends Per Share, Declared | CAD 1.0625 |  |
Preferred Stock, Redemption Price Per Share | CAD 25 |  |
Preferred Stock, Shares Outstanding | 8,000,000 | 8,000,000 |
Proceeds From Issuance Of Preferred Stock And Preference Stock Net | CAD 195.0 | CAD 195.0 |

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- Definition Describes the declaration as being a special dividend (over and above the normal dividend); as the annual, semi-annual, quarterly dividend, or other normal periodic dividend; or as some other type of dividend. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4313-108586 + Details
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- Definition The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644 + Details
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