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Financial Instruments and Risk Management (Fair Value for Assets and Liabilities) (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Disclosure of fair value measurement of assets [line items] |  |
Total liabilities | $ (1,751.9) | $ (1,077.7)
Total Assets | 5,336.1 | 4,001.2
Derivative financial assets | 0.0 | 6.6
Derivative financial liabilities | (149.1) | 1.0
Current derivative financial liabilities | 9.1 | 1.0
Non-current derivative financial liabilities | 140.0 | 0.0
Derivatives | Gold Options |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial assets, at fair value | (0.8) |
Derivatives | Currency Hedging Derivative Instruments |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities, at fair value | (9.0) |
Derivatives | Fuel Options |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial assets, at fair value | 0.1 | 0.2
Level 3 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Fair value, net asset (liability) | 0.0 | 0.0
Level 2 | Gold Forward Contracts |  |
Disclosure of fair value measurement of assets [line items] |  |
Total liabilities | (140.0) | 0.0
Level 2 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Fair value, net asset (liability) | (149.1) | 5.2
Level 2 | Recurring fair value measurement | Fair value through profit or loss | Gold Options |  |
Disclosure of fair value measurement of assets [line items] |  |
Total liabilities |  | 0.8
Level 2 | Recurring fair value measurement | Fair value through profit or loss | Share Purchase Warrants |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities, at fair value |  | (0.4)
Level 2 | Recurring fair value measurement | Fair value through OCI | Currency Hedging Derivative Instruments |  |
Disclosure of fair value measurement of assets [line items] |  |
Total liabilities |  | (6.6)
Level 1 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Fair value, net asset (liability) | 24.0 | 13.0
Level 1 | Recurring fair value measurement | Trading securities | Fair value through OCI |  |
Disclosure of fair value measurement of assets [line items] |  |
Total Assets | $ 24.0 | $ 13.0

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