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Inventory (Tables) | 12 Months Ended
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Dec. 31, 2017
Disclosure of inventories [Abstract] |
Schedule of Inventory |
| December 31, 2017 | December 31, 2016
In-process precious metals | $131.6 |  | $120.7 |
Ore in stockpiles | 44.1 |  | 37.6 |
Parts and supplies | 41.5 |  | 35.7 |
Dore, refined precious metals and gold in concentrate | 12.7 |  | 13.5 |
| 229.9 |  | 207.5 |
Less: Long-term inventory | (68.7 | ) | (75.8 | )
| $161.2 |  | $131.7 |

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