Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Disclosure of inventories [Abstract]
In-process precious metals	$ 53.6	$ 131.6
Ore in stockpiles	35.4	44.1
Parts and supplies	45.7	41.5
Dore, refined precious metals and gold in concentrate	5.5	12.7
Inventories	140.2	229.9
Less: Long-term inventory	(30.0)	(68.7)
Inventory	$ 110.2	$ 161.2

Disclosure of inventories [Abstract]

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Ore, Refined Precious Metals and Gold in Concentrate

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A classification of current inventory representing the amount of materials and supplies to be consumed in a production process or while rendering services. [Refer: Inventories]

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A classification of current inventory representing the amount of ore stockpiles. [Refer: Inventories]

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The amount of current inventories. [Refer: Inventories]

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The amount of assets: (a) held for sale in the ordinary course of business; (b) in the process of production for such sale; or (c) in the form of materials or supplies to be consumed in the production process or in the rendering of services. Inventories encompass goods purchased and held for resale including, for example, merchandise purchased by a retailer and held for resale, or land and other property held for resale. Inventories also encompass finished goods produced, or work in progress being produced, by the entity and include materials and supplies awaiting use in the production process. [Refer: Current finished goods; Current merchandise; Current work in progress; Land]

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