ACQUISITION (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Aug. 31, 2019 USD ($) payment shares	Sep. 30, 2019 USD ($) shares	Sep. 30, 2018 USD ($)	Aug. 31, 2019 $ / shares	Jun. 30, 2019 USD ($)
Acquisitions
Acquisition consideration paid		$ 4,362	$ 3
Investment value		$ 15,000			$ 16,000
TriStar
Acquisitions
Common stock that can be purchased by warrants (in shares) | shares		11,784,000
CDS
Acquisitions
Net smelter return (NSR) (as a percent)	1.50%
Acquisition consideration	$ 7,500
Number of installments | payment	3
Acquisition consideration paid	$ 4,500
First installment	1,500
Second installment	1,500
Acquisition payment, excluding associated costs	$ 4,400
CDS | TriStar
Acquisitions
Common stock that can be purchased by warrants (in shares) | shares	19,640,000	11,784,000
Investment value		$ 800
Exercise price of warrants | $ / shares				$ 0.25
Term of warrants	5 years