STREAM AND ROYALTY INTERESTS, NET (Details) $ in Thousands	Oct. 01, 2020 oz	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)
Stream and royalty interests, net		$ 2,242,314	$ 2,318,913
Wassa and Prestea
Stream and royalty interests, net		$ 75,900
Wassa | Initial Royalty
Gold streaming interest (as a percent)	10.50%
Gold delivered (in ounces) | oz	240,000
Spot price paid (as a percent)	20.00%
Wassa | Subsequent Royalty
Gold streaming interest (as a percent)	5.50%
Spot price paid (as a percent)	30.00%
Prestea and Bogoso
Gold streaming interest (as a percent)	5.50%
Spot price paid (as a percent)	30.00%