SHAREHOLDERS' EQUITY (Details) $ / shares in Units, $ in Thousands, $ in Millions										12 Months Ended
	Dec. 20, 2018 CAD ($) shares	Dec. 20, 2018 USD ($) $ / shares shares	Nov. 08, 2018 USD ($)	Jun. 11, 2018 shares	Dec. 20, 2017 USD ($)	Dec. 19, 2017 USD ($) $ / shares shares	Sep. 22, 2017 USD ($) item $ / shares shares	Apr. 26, 2017 $ / shares shares	Feb. 13, 2017	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares
Shareholders’ distributions										$ 3,372	$ 3,059	$ 2,986
Semi-annual shareholders’ distribution | $ / shares										0.010	0.010	0.005
Share repurchase program (in shares) | shares										0
Share repurchase program												$ 582
Common stock issued | shares										344,560,000	337,051,000
Shares of common stock issued upon exercise of stock options | shares										171	94	1,457
Weighted average exercise price of stock options (in dollars per share) | $ / shares										$ 1.02	$ 1.30	$ 2.48
Exercise of stock options										$ 192	$ 122	$ 3,730
Restricted cash										$ 14,685	10,000
Number of units issued | shares							20,700,000
Proceeds from equity sale (note 10)											42,453
Number of common stock reserved for issuance | shares										17,500,000
Number of warrants issued | item							10,350,000
Share price | $ / shares						$ 2.50
Net proceeds							$ 43,200			$ 918	39,397
Issuance costs							$ 3,400				3,353
Flow-through share premium received										$ 2,950	1,643
Warrants issued in connection with the equity issuance (note 10)											$ 3,823
Equity Incentive Plan
Common stock issued | shares										171,000	94,000
Weighted average exercise price of stock options (in dollars per share) | $ / shares										$ 1.02	$ 1.30
Common Stock
Shareholders’ distributions										$ 3,372	$ 3,059	$ 2,986
Share repurchase program (in shares) | shares												558
Share repurchase program												$ 582
Shares of common stock issued upon exercise of stock options | shares										182	94	1,494
Exercise of stock options										$ 192	$ 122	$ 3,730
Shares issued in connection with acquisitions (note 10) (in shares) | shares										178
Annual return of capital declared (in dollars per share) | $ / shares										$ 0.01	$ 0.010
Number of units issued | shares										515	20,700
Net proceeds										$ 918	$ 39,397
Warrants issued in connection with the equity issuance (note 10)											$ 3,823
Warrants
Number of common share per warrant | shares							1
Price per common share for each warrant | $ / shares							$ 2.70
Flow Through Common Shares
Restricted cash						$ 10,000				$ 0
Number of units issued | shares	6,634,000	6,634,000				4,000,000				6,634	4,000
Share price | $ / shares		$ 2.24
Net proceeds	$ 20.0	$ 14,900			$ 14,900					$ 11,145	$ 7,799
Issuance costs										800	500
Flow-through share premium received										$ 3,000	$ 1,600
At-the-market (“ATM”)
Number of units issued | shares										514,897
Proceeds from equity sale (note 10)										$ 900
Number of common stock reserved for issuance | shares										89,100,000
Aggregate offering price			$ 90,000
Lexam VG Gold
Shares issued in connection with acquisitions (note 10) (in shares) | shares								12,687,035
Ratio of Company's share for acquired company's share									0.056%
Number of units issued | shares								12,687,035
Share price | $ / shares								$ 3.00
Lexam VG Gold | Common Stock
Shares issued in connection with acquisitions (note 10) (in shares) | shares											12,687
Black Fox
Shares issued in connection with acquisitions (note 10) (in shares) | shares				178,321