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Other (Loss) Gain (Tables) | 12 Months Ended
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Dec. 31, 2018
Other Gain (Loss) [Abstract] |
Schedule of Other Nonoperating Income (Expense) | Other loss recorded in net (loss) earnings for the years ended:
| December 31, | December 31,
| 2018 | 2017
Reduction of obligation to renounce flow-through exploration expenditures | $0.6 |  | $2.3 |
Unrealized loss on non-hedging derivatives | (0.4 | ) | (0.3 | )
Loss on disposal of assets | (6.1 | ) | (1.9 | )
Transaction costs related to the Richmont acquisition (note 5) | — |  | (3.8 | )
Share-based compensation related of replacement awards related to Richmont (note 5) | — |  | (1.3 | )
Other | (2.5 | ) | 1.9 |
| ($8.4 | ) | ($3.1 | )

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