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SHAREHOLDERS' EQUITY (Details) $ / shares in Units, $ in Millions |  |  |  |  |  |  |  | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 20, 2019 USD ($) $ / shares shares | Mar. 29, 2019 USD ($) $ / shares shares | Dec. 20, 2018 CAD ($) shares | Dec. 20, 2018 USD ($) $ / shares shares | Nov. 08, 2018 USD ($) | Dec. 19, 2017 CAD ($) shares | Dec. 19, 2017 USD ($) $ / shares shares | Sep. 22, 2017 USD ($) item $ / shares shares | Apr. 26, 2017 USD ($) $ / shares shares | Mar. 31, 2019 USD ($) shares | Dec. 31, 2019 USD ($) $ / shares shares | Dec. 31, 2018 USD ($) $ / shares shares | Dec. 31, 2017 USD ($) $ / shares shares | Nov. 30, 2019 shares
Shareholders' distributions |  |  |  |  |  |  |  |  |  |  |  | $ 3,372,000 | $ 3,059,000 |
Semi-annual shareholders' distribution | $ / shares |  |  |  |  |  |  |  |  |  |  |  | 0.010 | 0.010 |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  | 400,339,000 | 344,560,000 |  |
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 1.01 | $ 1.02 | $ 1.30 |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  |  |  |  |  |  |  | 535,000 | 171,000 | 94,000 |
Exercise of stock options |  |  |  |  |  |  |  |  |  |  | $ 544,000 | $ 192,000 | $ 122,000 |
Proceeds from exercise of stock options |  |  |  |  |  |  |  |  |  |  | 544,000 | 192,000 | 121,000 |
Stock-based compensation |  |  |  |  |  |  |  |  |  |  | $ 694,000 | $ 269,000 | $ 1,311,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | shares |  |  |  |  |  |  |  |  |  |  | 3,050,000 | 375,000 | 338,000 |
Accounts payable and accrued liabilities |  |  |  |  |  |  |  |  |  |  | $ 34,070,000 | $ 30,817,000 |  |
Number of units issued | shares | 37,750,000 | 16,129,032 |  |  |  |  |  | 20,700,000 |  |  |  |  |  |
Sale of common stock for cash, net of issuance costs |  |  |  |  |  |  |  |  |  |  | $ 69,467,000 |  | $ 43,222,000 |
Number of common stock reserved for issuance | shares |  |  |  |  |  |  |  |  |  |  | 17,500,000 |  |  |
Percentage of equity acquired |  |  |  |  |  |  |  |  |  |  | 49.00% |  |  |
Number of warrants issued | item |  |  |  |  |  |  |  | 10,350,000 |  |  |  |  |  |
Price per unit | $ / shares | $ 1.325 | $ 1.55 |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds | $ 46,600,000 | $ 22,900,000 |  |  |  |  |  | $ 43,200,000 |  |  | $ 1,851,000 | 918,000 | 43,220,000 |
Income and mining tax recovery |  |  |  |  |  |  |  |  |  |  | (3,844,000) | (2,770,000) | $ (15,369,000) |
Issuance costs | $ 3,500,000 | $ 2,100,000 |  |  |  |  |  | 3,400,000 |  |  |  |  |  |
Flow-through share premium received |  |  |  |  |  |  |  |  |  |  |  | $ 2,950,000 |  |
Number of warrants received for each share of common stock share sold | shares |  | 0.50 |  |  |  |  |  |  |  |  |  |  |  | 0.50
Number of common stock | shares | 1 | 1 |  |  |  |  |  |  |  |  |  |  |  |
Outstanding warrants |  |  |  |  |  |  |  |  |  |  | $ 21,706,250 |  |  |
Shareholders' distribution declared per common share (note 13) | $ / shares |  |  |  |  |  |  |  |  |  |  |  | 0.010 | 0.010 |
Gold Bar mine |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  | 353,570 |  |  |
Equity Incentive Plan |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  | 535,000 | 171,000 |  |
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 1.02 | $ 1.02 |  |
Proceeds from exercise of stock options |  |  |  |  |  |  |  |  |  |  | $ 500,000 | $ 200,000 |  |
Lexam VG Gold |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in connection with acquisitions (in shares) | shares |  |  |  |  |  |  |  |  | 12,687,035 |  |  |  |  |
Common stock issued in connection with registered direct offering |  |  |  |  |  |  |  |  |  |  |  |  | $ 38,141,000 |
Accounts payable and accrued liabilities |  |  |  |  |  |  |  |  | $ 288,000 |  |  |  |  |
Number of units issued | shares |  |  |  |  |  |  |  |  | 12,687,035 |  |  |  |  |
Price per unit | $ / shares |  |  |  |  |  |  |  |  | $ 3.00 |  |  |  |  |
Black Fox |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in connection with acquisitions (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  | 178,321 |  |
Common Stock and Additional Paid-in Capital |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shareholders' distributions |  |  |  |  |  |  |  |  |  |  |  | $ 3,372,000 | $ 3,059,000 |
Annual return of capital declared (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  | $ 0.01 | $ 0.01 |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  |  |  |  |  |  |  | 535,000 | 182,000 | 94,000 |
Exercise of stock options |  |  |  |  |  |  |  |  |  |  | $ 544,000 | $ 192,000 | $ 122,000 |
Stock-based compensation |  |  |  |  |  |  |  |  |  |  | $ 694,000 | $ 269,000 | $ 1,311,000 |
Number of units issued | shares |  |  |  |  |  |  |  |  |  |  | 1,010,000 | 515,000 | 20,700,000 |
Net proceeds | $ 37,300,000 | $ 20,300,000 |  |  |  |  |  | 39,400,000 |  |  | $ 1,851,000 | $ 918,000 | $ 43,220,000 |
Shares of common stock issued as payment for mining concessions in Mexico | shares |  |  |  |  |  |  |  |  |  |  | 354,000 | 178,000 |  |
Common Stock and Additional Paid-in Capital | Lexam VG Gold |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in connection with acquisitions (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  | 12,687,000 |
Common stock issued in connection with registered direct offering |  |  |  |  |  |  |  |  |  |  |  |  | $ 38,141,000 |
Warrants |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds | $ 9,300,000 | $ 2,600,000 |  |  |  |  |  | $ 3,800,000 |  |  |  |  |  |
Number of common stock | shares | 1 | 1 |  |  |  |  |  | 1 |  |  |  |  |  |
Price per common share for each warrant | $ / shares | $ 1.7225 | $ 2.00 |  |  |  |  |  | $ 2.70 |  |  |  |  |  |
Warrants Expiration Term | 5 years | 3 years |  |  |  |  |  |  |  |  |  |  |  |
Subscription Receipts |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  | 1,935,484 |  |  |  |  |  |  |  |  |  |  |  |
Outstanding warrants |  |  |  |  |  |  |  |  |  |  | $ 8,064,516 |  |  |
Flow Through Common Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  |  | 6,634,000 | 6,634,000 |  | 4,000,000 | 4,000,000 |  |  |  |  | 6,634,000 | 4,000,000 |
Price per unit | $ / shares |  |  |  | $ 2.24 |  |  | $ 2.50 |  |  |  |  |  |  |
Net proceeds |  |  | $ 20.0 | $ 14,900,000 |  |  |  |  |  |  |  | $ 11,145,000 | $ 7,799,000 |
Gross proceeds |  |  |  |  |  | $ 12.9 | $ 10,000,000.0 |  |  |  |  |  |  |
Flow-through share premium received |  |  |  |  |  |  |  |  |  |  |  | 3,000,000.0 | 1,600,000 |
Flow Through Common Shares | Flow Through Common Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  |  |  |  |  |  |  |  | $ 14,100,000 | $ 9,400,000 |
At-the-market ("ATM") |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  |  |  |  |  |  |  |  |  | 1,010,545 |  | 514,897 |  |
Sale of common stock for cash, net of issuance costs |  |  |  |  |  |  |  |  |  | $ 1,900,000 |  | $ 900,000 |  |
Aggregate offering price |  |  |  |  | $ 90,000,000.0 |  |  |  |  |  |  |  |  |

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