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SHAREHOLDERS' EQUITY (Details) $ in Millions |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
May 23, 2019 USD ($) shares | Mar. 29, 2019 USD ($) $ / shares shares | Dec. 20, 2018 CAD ($) | Dec. 20, 2018 USD ($) $ / shares shares | Nov. 08, 2018 USD ($) | Dec. 19, 2017 CAD ($) | Dec. 19, 2017 USD ($) $ / shares shares | Dec. 31, 2019 CAD ($) | Dec. 31, 2019 USD ($) | Sep. 30, 2019 USD ($) shares | Mar. 31, 2019 USD ($) shares | Sep. 30, 2018 USD ($) $ / shares shares | Sep. 30, 2019 CAD ($) shares | Sep. 30, 2019 USD ($) $ / shares shares | Sep. 30, 2018 CAD ($) shares | Sep. 30, 2018 USD ($) $ / shares shares | Dec. 31, 2017 $ / shares | Sep. 30, 2019 USD ($) shares | Jun. 30, 2019 USD ($) | Dec. 31, 2018 USD ($) shares | Jun. 30, 2018 USD ($) | Jun. 11, 2018 shares
Shareholders' distributions |  |  |  |  |  |  |  |  |  |  |  | $ 1,687,000 |  |  |  | $ 3,373,000 |  |  |  |  |  |
Semi-annual shareholders' distribution | $ / shares |  |  |  |  |  |  |  |  |  |  |  | 0.005 |  |  |  | 0.010 | 0.01 |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  |  |  | 362,458,000 |  |  |  |  | 362,458,000 |  | 344,560,000 |  |
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1.01 |  | $ 1.17 |  |  |  |  |  |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  |  |  |  |  |  |  |  |  | 405,000 | 405,000 | 57,199 | 57,199 |  |  |  |  |  |
Exercise of stock options |  |  |  |  |  |  |  |  |  | $ 151,000 |  | $ 18,000 |  | $ 411,000 |  | $ 63,000 |  |  |  |  |  |
Proceeds from exercise of stock options |  |  |  |  |  |  |  |  |  |  |  |  |  | 411,000 |  | 63,000 |  |  |  |  |  |
Stock-based compensation |  |  |  |  |  |  |  |  |  | 284,000 |  | (214,000) |  | 481,000 |  | 182,000 |  |  |  |  |  |
Stock options granted |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,050,000 |  |  |  |  |  |  |  |
Accounts payable and accrued liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 32,110,000 |  | $ 30,817,000 |  |
Number of units issued | shares | 1,935,484 | 14,193,548 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Price per unit | $ / shares |  | $ 1.55 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds |  | $ 20,300,000 |  |  |  |  |  |  |  |  |  |  |  | 22,900,000 |  |  |  |  |  |  |  |
Share capital |  |  |  |  |  |  |  |  |  |  |  | 494,655,000 |  |  |  | 494,655,000 |  | 477,708,000 | $ 488,014,000 | 485,946,000 | $ 509,828,000 |
Income and mining tax recovery |  |  |  |  |  |  |  |  |  | $ (2,192,000) |  | $ (1,613,000) |  | $ (2,575,000) |  | $ (4,891,000) |  |  |  |  |  |
Issuance costs | $ 300,000 | $ 1,700,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Flow-through share premium received |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 839,000 |  | 2,950,000 |  |
Number of warrants received for each share of common stock share sold | shares |  | 0.50 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of common share per warrant | shares |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding warrants |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8,064,516 |  |  |  |
Shareholders' distribution declared per common share (note 12) | $ / shares |  |  |  |  |  |  |  |  |  |  |  | 0.005 |  |  |  | 0.010 | 0.01 |  |  |  |  |
Gold Bar mine |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  |  | 353,570 |  |  |  | 353,570 |  |  |  |  |  |
Black Fox |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 178,321
Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from exercise of stock options |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000 |  |  |  |  |  |
Officers, directors and certain employees |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1.72 |  |  |  |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shareholders' distributions |  |  |  |  |  |  |  |  |  |  |  | $ 1,687,000 |  |  |  | $ 3,373,000 |  |  |  |  |  |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  |  |  |  |  |  | 147,000 |  | 18,000 | 405,000 | 405,000 | 57,000 | 57,000 |  |  |  |  |  |
Exercise of stock options |  |  |  |  |  |  |  |  |  | $ 151,000 |  | $ 18,000 |  | $ 411,000 |  | $ 63,000 |  |  |  |  |  |
Stock-based compensation |  |  |  |  |  |  |  |  |  | $ 284,000 |  | (214,000) |  | 481,000 |  | 182,000 |  |  |  |  |  |
Net proceeds |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20,300,000 |  |  |  |  |  |  |  |
Share capital |  |  |  |  |  |  |  |  |  |  |  | $ 1,445,142,000 |  |  |  | $ 1,445,142,000 |  | 1,483,799,000 | $ 1,482,640,000 | $ 1,457,422,000 | $ 1,447,025,000 |
Shares of common stock issued as payment for mining concessions in Mexico | shares |  |  |  |  |  |  |  |  |  | 354,000 |  |  | 354,000 | 354,000 | 178,000 | 178,000 |  |  |  |  |  |
Warrants |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,600,000 |  |  |  |  |  |  |  |
Number of common share per warrant | shares |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Price per common share for each warrant | $ / shares |  | $ 2.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants Expiration Term |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subscription Receipts |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  | 1,935,484 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Price per unit | $ / shares |  | $ 1.55 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds | $ 2,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units received upon necessary shareholder and NYSE approvals | shares |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Flow Through Common Shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  | 6,634,000 |  |  | 4,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Price per unit | $ / shares |  |  |  | $ 2.24 |  |  | $ 2.50 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds |  |  |  | $ 14,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share capital |  |  |  | 11,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Income and mining tax recovery |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,100,000 |  | $ 1,600,000 |  |  |  |  |  |
Gross proceeds |  |  | $ 20.0 | 14,900,000 |  | $ 12.9 | $ 10,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Flow-through share premium received |  |  |  | $ 3,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Flow Through CEE |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Accounts payable and accrued liabilities |  |  |  |  |  |  |  |  |  |  |  |  | $ 6.2 |  |  |  |  | $ 4,700,000 |  |  |  |
Flow through expenditure incurred |  |  |  |  |  |  |  | $ 5.3 | $ 3,900,000 |  |  |  | $ 14.7 | 11,000,000.0 | $ 16.1 | $ 12,400,000 |  |  |  |  |  |
ATM offering |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  |  | 1,010,545 |  |  |  |  |  |  |  |  |  |  |
Aggregate offering price |  |  |  |  | $ 90,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  |  |  |  |  |  |  | $ 1,900,000 |  |  | $ 1,851,000 |  |  |  |  |  |  |  |
ATM offering | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  |  |  |  |  |  |  |  |  |  |  |  | 1,010,000 | 1,010,000 |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,851,000 |  |  |  |  |  |  |  |

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