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Amounts Receivable (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Subclassifications of assets, liabilities and equities [abstract] |
Schedule of Receivables |
| December 31, 2017 | December 31, 2016
Sales tax receivables |  |  |
Canada | $6.4 |  | $2.3 |
Mexico | 20.0 |  | 36.2 |
Other | 0.9 |  | 0.5 |
Concentrate receivable | 3.2 |  | 2.2 |
Other receivables | 4.0 |  | 3.7 |
| $34.5 |  | $44.9 |

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