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Consolidated Statements of Changes in Equity - USD ($) $ in Millions | Total | Share capital [Member] | Contributed Surplus [member] | Accumulated other comprehensive income (loss) [member] | Accumulated other comprehensive income (loss) [member] Equity securities [member] | Accumulated other comprehensive income (loss) [member] Currency hedging instruments [member] | Accumulated other comprehensive income (loss) [member] Fuel Hedging Instruments [Member] | Deficit [member]
--- | --- | --- | --- | --- | --- | --- | --- | ---
Beginning balance at Dec. 31, 2018 |  | $ 3,705.2 | $ 87.3 |  | $ (7.3) | $ (1.4) | $ (0.5) | $ (1,184.9)
Changes in equity [abstract] |  |  |  |  |  |  |  |
Repurchase and cancellation of common shares (note 11) |  | (26.1) |  |  |  |  |  | 14.7
Issuance of shares related to share-based compensation |  | 7.0 |  |  |  |  |  |
Issuance of shares related to dividend reinvestment and share purchase plan |  | 0.0 |  |  |  |  |  |
Share-based compensation |  |  | 5.8 |  |  |  |  |
Transfer from contributed surplus of share-based compensation redeemed |  | 2.5 | (2.5) |  |  |  |  |
Stock Issued During Period, Value, Issued Flow-through Share Agreement |  | 5.9 |  |  |  |  |  |
Stock Issued During Period, Value, Merger |  |  | (3.8) |  |  |  |  |
Stock Reclassified Due to Expiration of Warrants |  |  | 3.9 |  |  |  |  |
Realized gain on sale of equity securities, reclassified to deficit |  |  |  |  | 0.0 |  |  |
Unrealized gain on equity securities, net of taxes |  |  |  |  | 2.5 |  |  |
Dividends (note 11(f)) | $ 15.6 |  |  |  |  |  |  | (15.6)
Reclassification of realized gain on sale of equity securities, net of tax |  |  |  |  |  |  |  | 0.0
Cancellation of unexchanged post-amalgamation shares |  | (1.2) |  |  |  |  |  | 1.2
Net earnings | 96.1 |  |  |  |  |  |  | 96.1
Hedging gains (losses) for hedge of group of items with offsetting risk positions |  |  |  |  |  | 6.0 | 0.5 |
Ending balance at Dec. 31, 2019 | 2,695.3 | 3,693.3 | 90.7 | $ (0.2) | (4.8) | 4.6 | 0.0 | (1,088.5)
Changes in equity [abstract] |  |  |  |  |  |  |  |
Repurchase and cancellation of common shares (note 11) |  | (10.7) |  |  |  |  |  | 5.2
Issuance of shares related to share-based compensation |  | 7.5 |  |  |  |  |  |
Issuance of shares related to dividend reinvestment and share purchase plan |  | 10.0 |  |  |  |  |  |
Share-based compensation |  |  | 4.1 |  |  |  |  |
Transfer from contributed surplus of share-based compensation redeemed |  | 2.8 | (2.8) |  |  |  |  |
Stock Issued During Period, Value, Issued Flow-through Share Agreement |  | 0.0 |  |  |  |  |  |
Stock Issued During Period, Value, Merger |  |  | (3.5) |  |  |  |  |
Stock Reclassified Due to Expiration of Warrants |  |  | 0.0 |  |  |  |  |
Realized gain on sale of equity securities, reclassified to deficit |  |  |  |  | (6.6) |  |  |
Unrealized gain on equity securities, net of taxes |  |  |  |  | 23.8 |  |  |
Dividends (note 11(f)) | 1.7 |  |  |  |  |  |  | (25.6)
Reclassification of realized gain on sale of equity securities, net of tax |  |  |  |  |  |  |  | 6.6
Cancellation of unexchanged post-amalgamation shares |  | 0.0 |  |  |  |  |  | 0.0
Net earnings | 144.2 |  |  |  |  |  |  |
Hedging gains (losses) for hedge of group of items with offsetting risk positions |  |  |  |  |  | 1.1 | 0.1 |
Ending balance at Dec. 31, 2020 | $ 2,851.5 | $ 3,702.9 | $ 88.5 | $ 18.2 | $ 12.4 | $ 5.7 | $ 0.1 | $ (958.1)

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