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Impairment charge (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2021 | Dec. 31, 2021 | Dec. 31, 2020
Disclosure of impairment loss and reversal of impairment loss [line items] |  |  |
Pre-tax impairment charge |  | $ 224.3 | $ 0.0
Deferred tax liability |  | (10.5) |
After-tax impairment charge | $ 213.8 | 213.8 |
Current assets |  |  |
Disclosure of impairment loss and reversal of impairment loss [line items] |  |  |
Pre-tax impairment charge |  | 5.5 |
Plant and equipment |  |  |
Disclosure of impairment loss and reversal of impairment loss [line items] |  |  |
Pre-tax impairment charge |  | 0.3 |
Mineral property - non-depletable |  |  |
Disclosure of impairment loss and reversal of impairment loss [line items] |  |  |
Pre-tax impairment charge |  | 142.4 |
Exploration and evaluation |  |  |
Disclosure of impairment loss and reversal of impairment loss [line items] |  |  |
Pre-tax impairment charge |  | $ 76.1 |

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- Definition Deferred tax liabilities recognised after impairment charge + References No definition available. + Details
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- Definition Impairment loss recognised in profit or loss, net + References No definition available. + Details
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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The amount of impairment loss or reversal of impairment loss recognised in profit or loss. [Refer: Impairment loss recognised in profit or loss; Reversal of impairment loss recognised in profit or loss] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 99 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_99&doctype=Standard -URIDate 2021-03-24 + Details
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