SHAREHOLDERS' EQUITY (Details) $ in Millions					3 Months Ended		9 Months Ended	12 Months Ended
	Mar. 29, 2019 USD ($) $ / shares shares	Dec. 20, 2018 USD ($) $ / shares shares	Nov. 08, 2018 USD ($)	Dec. 19, 2017 USD ($) $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2018 USD ($) $ / shares shares	Sep. 30, 2018 $ / shares	Dec. 31, 2018 CAD ($)	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 CAD ($)	Dec. 31, 2017 USD ($)
Shareholders’ distributions						$ 1,686,000
Semi-annual shareholders’ distribution | $ / shares						0.005	0.005
Common stock issued | shares					359,986,000				344,560,000
Exercise of stock options					$ 223,000	$ 40,000
Restricted cash					14,762,000				$ 14,685,000
Number of units issued | shares	14,193,548
Sale of common stock for cash, net of issuance costs					19,320,000
Price per unit | $ / shares	$ 1.55
Net proceeds	$ 20,300,000
Issuance costs	$ 1,700,000				1,748,000
Flow-through share premium received					2,893,000				2,950,000
Number of warrants received for each share of common stock share sold | shares	0.50
Number of common share per warrant | shares	1
Outstanding warrants					7,096,774	$ 10,350,000
Warrants issued in connection with registered direct offering (note 8)					$ 2,467,000
Equity Incentive Plan
Shares of common stock issued upon exercise of stock options | shares					221,500	35,199
Weighted average exercise price of stock options (in dollars per share) | $ / shares					$ 1.00	$ 1.15
Exercise of stock options					$ 200,000	$ 100,000
Common Stock
Shareholders’ distributions						$ 1,686,000
Shares of common stock issued upon exercise of stock options | shares					222,000	35,000
Exercise of stock options					$ 223,000	$ 40,000
Common stock issued in connection with registered direct offering (note 8) (in shares) | shares					14,194,000
Warrants
Number of common share per warrant | shares	1
Price per common share for each warrant | $ / shares	$ 2.00
Warrants issued in connection with registered direct offering (note 8)					$ 2,467,000
Subscription Receipts
Number of units issued | shares	1,935,484
Price per unit | $ / shares	$ 1.55
Net proceeds	$ 2,800,000
Gross proceeds	$ 3,000,000
Number of units per subscription receipt | shares	1
Flow Through Common Shares
Decrease in flow through premium					100,000	600,000
Number of units issued | shares		6,634,000		4,000,000
Price per unit | $ / shares		$ 2.24		$ 2.50
Net proceeds		$ 14,900,000		$ 10,000,000				$ 20.0	14,900,000	$ 12.9	$ 10,000,000
Flow-through share premium received									$ 3,000,000
Restricted cash spent for Timmins exploration activities					$ 400,000	1,200,000
At-the-market (“ATM”)
Number of units issued | shares					1,010,000
Sale of common stock for cash, net of issuance costs						$ 0
Aggregate offering price			$ 90,000,000
Net proceeds					$ 1,851,000