SHAREHOLDERS' EQUITY (Details) $ / shares in Units, $ in Thousands, $ in Millions					3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 11, 2018 shares	Dec. 19, 2017 USD ($) $ / shares shares	Sep. 22, 2017 USD ($) item $ / shares shares	Apr. 26, 2017 shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) $ / shares shares	Dec. 31, 2017 CAD ($)	Dec. 31, 2017 USD ($) shares
Shareholders’ distributions					$ 1,687	$ 1,561	$ 3,372	$ 3,059
Semi-annual shareholders’ distribution | $ / shares					0.005	0.005	0.010	0.010
Common stock issued | shares					337,286,000		337,286,000			337,051,000
Exercise of stock options					$ 18		$ 63	$ 47
Flow-through share premium										$ 1,643
Restricted cash										10,000
Number of units issued | shares			20,700,000
Number of warrants issued | item			10,350,000
Net proceeds			$ 43,200			$ 39,397	$ 39,400	39,397
Issuance costs								3,353
Number of warrants received for each share of common stock share sold | shares			0.5
Warrants issued in connection with the equity sale (note 8)						3,823		$ 3,823
Number of warrants remained outstanding and unexercised | shares					10,350,000		10,350,000
Equity Incentive Plan
Shares of common stock issued upon exercise of stock options | shares							57,199	20,000
Weighted average exercise price of stock options (in dollars per share) | $ / shares							$ 1.17	$ 2.34
Exercise of stock options							$ 100	$ 100
Common Stock
Shareholders’ distributions					$ 1,687	$ 1,561	$ 3,372	$ 3,059
Shares of common stock issued upon exercise of stock options | shares					18,000		57,000	20,000
Exercise of stock options					$ 18		$ 63	$ 47
Number of units issued | shares						20,700,000		20,700,000
Net proceeds						$ 39,397		$ 39,397
Warrants issued in connection with the equity sale (note 8)						$ 3,823		$ 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
Flow-through share premium		$ 1,600			0		0
Restricted cash					$ 0		0
Decrease in flow through premium							$ 1,600
Number of units issued | shares		4,000,000
Price per unit | $ / shares		$ 2.50
Net proceeds		$ 10,000							$ 12.9	$ 10,000
Share price | $ / shares		$ 2.50
Lexam
Ratio of Company's share for acquired company's share				0.056%
Lexam | Warrants
Number of units issued | shares				12,687,035
Percentage of equity acquired				100.00%
Black Fox
Number of units issued | shares	178,321
Black Fox | Common Stock
Shares issued in connection with the acquisition (note 8) (in shares) | shares							178,000