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Amounts Receivable (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Receivables [Line Items] |  |
Other receivables | $ 7.6 | $ 4.7
Trade and other current receivables | 34.7 | 37.4
Canada |  |
Receivables [Line Items] |  |
Sales tax receivables | 5.4 | 8.9
Mexico |  |
Receivables [Line Items] |  |
Sales tax receivables | 17.7 | 18.1
Other |  |
Receivables [Line Items] |  |
Sales tax receivables | $ 4.0 | $ 5.7

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