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Note 16 - Acquisitions (Details Textual) $ / shares in Units, $ in Thousands |  |  | 3 Months Ended | 12 Months Ended | 58 Months Ended
--- | --- | --- | --- | --- | ---
Jul. 20, 2018 USD ($) $ / shares shares | Jul. 19, 2018 shares | Dec. 31, 2019 shares | Jun. 30, 2019 USD ($) | Dec. 31, 2019 shares | Dec. 31, 2018 shares | Dec. 31, 2020 shares
Common Stock, Shares, Issued, Total (in shares) | shares |  |  |  |  |  |  | 538,487,415
Stock Issued During Period, Shares, New Issues (in shares) | shares |  |  | 21,410,231 |  | 21,410,000 | 2,565,000 | 28,583,845
Warrants in Connection with Klondex Mines Acquisition [Member] |  |  |  |  |  |  |
Class of Warrant or Right, Issued During Period (in shares) | shares | 4,136,000 |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares | 1 |  |  |  |  |  |
Warrants in Connection with Klondex Mines Acquisition Expiring April 2032 [Member] |  |  |  |  |  |  |
Class of Warrant or Right, Outstanding (in shares) | shares | 2,068,000 |  |  |  |  |  |
Warrants in Connection with Klondex Mines Acquisition Expiring February 2029 [Member] |  |  |  |  |  |  |
Class of Warrant or Right, Outstanding (in shares) | shares | 2,068,000 |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 1.57 |  |  |  |  |  |
Klondex Mines Ltd [Member] |  |  |  |  |  |  |
Common Stock, Shares, Issued, Total (in shares) | shares | 182,048,945 | 180,499,319 |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares |  | 1,549,626 |  |  |  |  |
Klondex Mines Ltd [Member] |  |  |  |  |  |  |
Business Acquisition, Share Price (in dollars per share) | $ / shares | $ 2.27 |  |  |  |  |  |
Business Acquisition, Percentage of Voting Interests Acquired | 100.00% |  |  |  |  |  |
Business Combination, Consideration, Cash Alternative, Price Per Share (in dollars per share) | $ / shares | $ 2.47 |  |  |  |  |  |
Business Combination, Consideration, Share Alternative, Share Exchange Rate | 0.6272 |  |  |  |  |  |
Business Combination Consideration, Combined Alternative, Price Per Share (in dollars per share) | $ / shares | $ 0.8411 |  |  |  |  |  |
Business Combination Consideration, Combined Alternative, Share Exchange Rate | 0.4136 |  |  |  |  |  |
Payments to Acquire Businesses, Gross | $ 161,704 |  |  |  |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares | 75,276,176 |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares | 75,276,176 |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares | $ 8.02 |  |  |  |  |  |
Share-based Payment Arrangement, Cash Used to Settle Award | $ 2,000 |  |  |  |  |  |
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable | 242,389 |  |  |  |  |  |
Class of Warrant or Right, Issued During Period, Value | 9,800 |  |  |  |  |  |
Business Combination, Consideration Transferred, Total | 413,923 |  |  |  |  |  |
Business Combination, Subscrition of New Formed Company, Value | 7,000 |  |  |  |  |  |
Business Combination, Settlement of Certain Equity Compensation Value | 1,500 |  |  |  |  |  |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred |  |  |  | $ (300) |  |  |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory |  |  |  | (200) |  |  |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment |  |  |  | (11,500) |  |  |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accrued Payroll and Related Benefits |  |  |  | (2,100) |  |  |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Noncurrent Deferred Tax Liability |  |  |  | (9,800) |  |  |
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accounts Payable and Accrued Liabilities |  |  |  | $ 500 |  |  |
Klondex Mines Ltd [Member] | Maximum [Member] |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross | $ 153,200 |  |  |  |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares | 75,276,176 |  |  |  |  |  |

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