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COMMITMENTS AND CONTINGENCIES - Surety, Reclamation Bonds and Flow-Through Common Shares (Details) $ in Thousands, $ in Millions |  |  |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Mar. 29, 2019 USD ($) | Dec. 20, 2018 USD ($) | Dec. 19, 2017 USD ($) | Mar. 31, 2019 CAD ($) | Mar. 31, 2019 USD ($) | Mar. 31, 2018 USD ($) | Dec. 31, 2018 CAD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 CAD ($) | Dec. 31, 2017 USD ($)
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Other assets |  |  |  |  | $ 4,173 |  |  | $ 5,872 |  |
Amount raised or spent in connection with the equity issuance | $ 20,300 |  |  |  |  |  |  |  |  |
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Reclamation bonding obligation |  |  |  |  | $ 19,900 |  |  |  |  |
Black Fox | Surety Bonds |  |  |  |  |  |  |  |  |  |
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Percentage of annual fees on surety bonds |  |  |  | 2.00% | 2.00% |  |  |  |  |
Percentage of upfront deposit on surety bonds |  |  |  | 0.00% | 0.00% |  |  |  |  |
Surety bonding obligation |  |  |  | $ 20.6 | $ 15,400 |  |  |  |  |
Outstanding surety bonds |  |  |  |  | 20,000 |  |  |  |  |
Black Fox | Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Surety bonding obligation |  |  |  | $ 20.6 | 15,400 |  |  |  |  |
Timmins | Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Surety bonds upfront deposit amount |  |  |  |  | 100 |  |  |  |  |
Flow Through Common Shares |  |  |  |  |  |  |  |  |  |
Reclamation Bonds |  |  |  |  |  |  |  |  |  |
Amount raised or spent in connection with the equity issuance |  | $ 14,900 | $ 10,000 |  |  |  | $ 20.0 | $ 14,900 | $ 12.9 | $ 10,000
Total costs incurred for Canadian Exploration Expenditures |  |  |  |  | $ 400 | $ 1,200 |  |  |  |

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- Definition It is a type of performance surety bond. This type of surety bond is required by the Bureau of Land Management (BLM) and also by some state government agencies that issue permits for mining type operations. Reclamation bond amounts are not standard. + References No definition available. + Details
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- Definition Represents a surety bond obligation. It is a promise by a surety or guarantor to pay one party (the obligee) a certain amount if a second party (the principal) fails to meet some obligation, such as fulfilling the terms of a contract. + References No definition available. + Details
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