STREAM AND ROYALTY INTERESTS, NET (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019
Stream and royalty interests, net	$ 2,305,018	$ 2,339,316
Mount Milligan
Gold streaming interest (as a percent)	35.00%
Copper streaming interest (as a percent)	18.75%
Stream and royalty interests, net	$ 597,900
El Toqui
Stream and royalty interests, net	1,400
Evaluation stage property
Stream and royalty interests, net	$ 2,700