REVENUE - Property Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue
Revenue	$ 162,355	$ 142,589
Stream interests
Disaggregation of Revenue
Revenue	105,251	95,346
Stream interests | Mt. Milligan
Disaggregation of Revenue
Revenue	42,416	33,803
Stream interests | Pueblo Viejo
Disaggregation of Revenue
Revenue	23,264	30,173
Stream interests | Andacollo
Disaggregation of Revenue
Revenue	15,674	13,022
Stream interests | Wassa
Disaggregation of Revenue
Revenue	7,202	8,774
Stream interests | Khoemacau
Disaggregation of Revenue
Revenue	2,389
Stream interests | Other Mines
Disaggregation of Revenue
Revenue	14,306	9,574
Royalty interests
Disaggregation of Revenue
Revenue	57,104	47,243
Royalty interests | Cortez
Disaggregation of Revenue
Revenue	16,714	8,609
Royalty interests | Penasquito
Disaggregation of Revenue
Revenue	13,094	13,128
Royalty interests | Other Mines
Disaggregation of Revenue
Revenue	$ 27,296	$ 25,506