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SHAREHOLDERS' EQUITY (Details) $ in Millions |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | ---
Mar. 29, 2019 USD ($) $ / shares shares | Dec. 20, 2018 USD ($) $ / shares shares | Nov. 08, 2018 USD ($) | Dec. 19, 2017 USD ($) $ / shares shares | Mar. 31, 2019 USD ($) $ / shares shares | Mar. 31, 2018 USD ($) $ / shares shares | Sep. 30, 2018 $ / shares | Dec. 31, 2018 CAD ($) | Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 CAD ($) | Dec. 31, 2017 USD ($)
Shareholders’ distributions |  |  |  |  |  | $ 1,686,000 |  |  |  |  |
Semi-annual shareholders’ distribution | $ / shares |  |  |  |  |  | 0.005 | 0.005 |  |  |  |
Common stock issued | shares |  |  |  |  | 359,986,000 |  |  |  | 344,560,000 |  |
Exercise of stock options |  |  |  |  | $ 223,000 | $ 40,000 |  |  |  |  |
Restricted cash |  |  |  |  | 14,762,000 |  |  |  | $ 14,685,000 |  |
Number of units issued | shares | 14,193,548 |  |  |  |  |  |  |  |  |  |
Sale of common stock for cash, net of issuance costs |  |  |  |  | 19,320,000 |  |  |  |  |  |
Price per unit | $ / shares | $ 1.55 |  |  |  |  |  |  |  |  |  |
Net proceeds | $ 20,300,000 |  |  |  |  |  |  |  |  |  |
Issuance costs | $ 1,700,000 |  |  |  | 1,748,000 |  |  |  |  |  |
Flow-through share premium received |  |  |  |  | 2,893,000 |  |  |  | 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 |  |  |  |  | 7,096,774 | $ 10,350,000 |  |  |  |  |
Warrants issued in connection with registered direct offering (note 8) |  |  |  |  | $ 2,467,000 |  |  |  |  |  |
Equity Incentive Plan |  |  |  |  |  |  |  |  |  |  |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  | 221,500 | 35,199 |  |  |  |  |
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  | $ 1.00 | $ 1.15 |  |  |  |  |
Exercise of stock options |  |  |  |  | $ 200,000 | $ 100,000 |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |
Shareholders’ distributions |  |  |  |  |  | $ 1,686,000 |  |  |  |  |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  | 222,000 | 35,000 |  |  |  |  |
Exercise of stock options |  |  |  |  | $ 223,000 | $ 40,000 |  |  |  |  |
Common stock issued in connection with registered direct offering (note 8) (in shares) | shares |  |  |  |  | 14,194,000 |  |  |  |  |  |
Warrants |  |  |  |  |  |  |  |  |  |  |
Number of common share per warrant | shares | 1 |  |  |  |  |  |  |  |  |  |
Price per common share for each warrant | $ / shares | $ 2.00 |  |  |  |  |  |  |  |  |  |
Warrants issued in connection with registered direct offering (note 8) |  |  |  |  | $ 2,467,000 |  |  |  |  |  |
Subscription Receipts |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares | 1,935,484 |  |  |  |  |  |  |  |  |  |
Price per unit | $ / shares | $ 1.55 |  |  |  |  |  |  |  |  |  |
Net proceeds | $ 2,800,000 |  |  |  |  |  |  |  |  |  |
Gross proceeds | $ 3,000,000 |  |  |  |  |  |  |  |  |  |
Number of units per subscription receipt | shares | 1 |  |  |  |  |  |  |  |  |  |
Flow Through Common Shares |  |  |  |  |  |  |  |  |  |  |
Decrease in flow through premium |  |  |  |  | 100,000 | 600,000 |  |  |  |  |
Number of units issued | shares |  | 6,634,000 |  | 4,000,000 |  |  |  |  |  |  |
Price per unit | $ / shares |  | $ 2.24 |  | $ 2.50 |  |  |  |  |  |  |
Net proceeds |  | $ 14,900,000 |  | $ 10,000,000 |  |  |  | $ 20.0 | 14,900,000 | $ 12.9 | $ 10,000,000
Flow-through share premium received |  |  |  |  |  |  |  |  | $ 3,000,000 |  |
Restricted cash spent for Timmins exploration activities |  |  |  |  | $ 400,000 | 1,200,000 |  |  |  |  |
At-the-market (“ATM”) |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  |  |  |  | 1,010,000 |  |  |  |  |  |
Sale of common stock for cash, net of issuance costs |  |  |  |  |  | $ 0 |  |  |  |  |
Aggregate offering price |  |  | $ 90,000,000 |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  | $ 1,851,000 |  |  |  |  |  |

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