REVENUE - Metal Disaggregation (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue
Revenue	$ 342,952	$ 305,240	$ 615,856	$ 498,819	$ 423,056
Stream interests
Disaggregation of Revenue
Revenue	226,551		423,989	359,868	305,824
Stream interests | Gold
Disaggregation of Revenue
Revenue	165,031		323,980	294,490	249,496
Stream interests | Silver
Disaggregation of Revenue
Revenue	30,576		43,281	32,744	33,282
Stream interests | Copper
Disaggregation of Revenue
Revenue	30,944		56,728	32,634	23,046
Royalty interests
Disaggregation of Revenue
Revenue	116,401		191,867	138,951	117,232
Royalty interests | Gold
Disaggregation of Revenue
Revenue	85,151		131,784	98,153	78,570
Royalty interests | Silver
Disaggregation of Revenue
Revenue	8,253		16,198	9,996	5,497
Royalty interests | Copper
Disaggregation of Revenue
Revenue	9,511		16,448	13,528	13,808
Royalty interests | Other
Disaggregation of Revenue
Revenue	$ 13,486		$ 27,437	$ 17,274	$ 19,357