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