SEGMENTED INFORMATION - Geographic segments (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Segmented Information
Metal sales	$ 4,239.7	$ 3,455.1
Property, plant and equipment	7,963.2	7,741.4
United States
Segmented Information
Metal sales	1,361.9	1,315.0
Property, plant and equipment	1,668.6	1,629.4
Brazil
Segmented Information
Metal sales	1,149.6	935.0
Property, plant and equipment	1,658.8	1,518.6
Mauritania
Segmented Information
Metal sales	1,200.8	1,021.5
Property, plant and equipment	2,335.1	2,280.6
Chile
Segmented Information
Metal sales	527.4	183.6
Property, plant and equipment	804.8	910.3
Canada
Segmented Information
Property, plant and equipment	$ 1,495.9	$ 1,402.5

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The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. Note that right-of-use assets are not included. [Contrast: Property, plant and equipment including right-of-use assets]

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The amount of revenue from contracts with customers. A customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration.

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