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Financial Instruments and Risk Management (Contractual Commitments) (Details) $ in Millions | Dec. 31, 2017 USD ($)
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Disclosure of detailed information about financial instruments [abstract] |
Operating and financing leases, less than 1 year | $ 5.4
Operating and financing leases, 2-3 years | 5.6
Operating and financing leases, 4-5 years | 2.0
Operating and financing leases, more than 5 years | 2.9
Operating and financing leases, total | 15.9
Accounts payable and accrued liabilities, less than 1 year | 96.8
Accounts payable and accrued liabilities, 2-3 years | 0.0
Accounts payable and accrued liabilities, 4-5 years | 0.0
Accounts payable and accrued liabilities, more than 5 years | 0.0
Accounts payable and accrued liabilities, total | 96.8
Decommissioning liability, less than 1 year | 0.0
Decommissioning liability, 2-3 years | 0.0
Decommissioning liability, 4-5 years | 0.0
Decommissioning liability, more than 5 years | 54.8
Decommissioning liability, total | 54.8
Contract mining, less than 1 year | 47.9
Contract mining, 2-3 years | 72.0
Contract mining, 4-5 years | 47.8
Contract mining, more than 5 years | 38.9
Contract mining, total | 206.6
Flow-through share obligation, less than 1 year | 0.7
Flow-through share obligation, 2-3 years | 0.0
Flow-through share obligation, 4-5 years | 0.0
Flow-through share obligation, more than 5 years | 0.0
Flow-through share obligations, total | 0.7
Capital commitments, less than 1 year | 21.8
Capital commitments, 2-3 years | 0.0
Capital commitments, 4-5 years | 0.0
Capital commitments, more than 5 years | 0.0
Capital commitments, total | 21.8
Contractual obligation, less than 1 year | 172.6
Contractual obligation, 2-3 years | 77.6
Contractual obligation, 4-5 years | 49.8
Contractual obligation, more than 5 years | 96.6
Contractual obligation, total | $ 396.6

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