SHAREHOLDERS' EQUITY (Details) $ / shares in Units, $ in Thousands, $ in Millions				3 Months Ended		12 Months Ended
	Dec. 19, 2017 USD ($) $ / shares shares	Sep. 22, 2017 USD ($) item $ / shares shares	Apr. 26, 2017 shares	Mar. 31, 2018 USD ($) $ / shares shares	Mar. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 CAD ($)	Dec. 31, 2017 USD ($) shares
Shareholders’ distributions				$ 1,686	$ 1,498
Common stock issued | shares				337,086,000			337,051,000
Weighted average exercise price of stock options (in dollars per share) | $ / shares				$ 1.15	$ 2.34
Exercise of stock options				$ 40	$ (47)
Flow-through share premium				1,000			$ 1,643
Restricted cash for exploration activities				1,200
Decrease in flow through premium				600
Number of units issued | shares		20,700,000
Number of warrants issued | item		10,350,000
Price per unit | $ / shares	$ 2.50
Net proceeds		$ 43,200		39,400
Issuance costs		$ 3,400		$ 3,800
Number of warrants remained outstanding and unexercised | shares				10,350,000
Share price | $ / shares	$ 2.50
Equity Incentive Plan
Shares of common stock issued upon exercise of stock options | shares					20,000
Common Stock
Shareholders’ distributions				$ 1,686	$ 1,498
Shares of common stock issued upon exercise of stock options | shares				35,000	20,000
Exercise of stock options				$ 40	$ (47)
Warrants
Number of common share per warrant | shares		1
Price per common share for each warrant | $ / shares		$ 2.70
Flow Through Common Shares
Flow-through share premium	$ 1,600
Number of units issued | shares	4,000,000
Net proceeds	$ 10,000			$ 1,200		$ 12.9	$ 10,000
Lexam
Ratio of Company's share for acquired company's share			0.056%
Lexam | Warrants
Number of units issued | shares			12,687,035
Equity Method Investment, Ownership Percentage			100.00%