SHAREHOLDERS' EQUITY - Equity Offerings (Details) $ / shares in Units, CAD in Thousands, $ in Thousands					12 Months Ended
	Dec. 19, 2017 CAD shares	Dec. 19, 2017 USD ($) $ / shares shares	Sep. 22, 2017 USD ($) item $ / shares shares	Apr. 26, 2017 $ / shares shares	Dec. 31, 2017 USD ($) shares
Number of units issued			20,700,000
Number of warrants issued | item			10,350,000
Price per unit | $ / shares		$ 2.50
Issuance expenses related to new stock issue | $			$ 3,400		$ 3,353
Net proceeds | $			43,200
Issuance costs | $			$ 3,400		$ 3,353
Number of warrants remained outstanding and unexercised					10,350,000
Common Stock
Number of units issued					20,700
Net proceeds | $					$ 39,397
Warrants
Number of common share per warrant			1
Price per common share for each warrant | $ / shares			$ 2.70
Flow Through Common Shares
Number of units issued	4,000,000	4,000,000			4,000
Net proceeds	CAD 12,880	$ 10,000			$ 7,799
Lexam
Number of units issued				12,687,035
Price per unit | $ / shares				$ 3.00