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Significant Events - Normal Course Issuer Bid (Details) - CAD ($) $ / shares in Units, $ in Millions | 6 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Apr. 30, 2019 | Dec. 31, 2019 | May 27, 2019 | Dec. 31, 2018 | Mar. 09, 2018
Investment [Line Items] |  |  |  |  |
Stock purchase agreement, Toronto Stock Exchange, twenty-five percent of daily trading volume | 705,788 |  |  |  |
NCIB Program |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Stock purchase agreement, number of shares authorized |  |  | 14,000,000 |  | 14,000,000
Stock purchase agreement, maximum shares purchase for a single trading day |  | 176,447 |  |  |
Number of shares issued and fully paid |  | 7,716,300 |  | 3,264,500 |
Par value per share |  | $ 8.80 |  | $ 7.02 |
Issued capital (Note 24) |  | $ 68 |  | $ 23 |

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