SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Long Lived Assets and Pre-Tax Income by Geographical Information
Number of reportable segments | segment			2
Stream and royalty interest	$ 3,084,380		$ 3,084,380		$ 2,443,752
Revenue	131,429	$ 174,431	440,226	$ 485,047
Cost of sales	23,221	27,230	69,670	73,367
Production taxes	1,119	2,054	4,765	6,042
Depletion	37,639	50,518	129,368	139,657
Total segment gross profit	69,450	94,629	236,423	265,981
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	1,148,360		1,148,360		991,745
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	328,674		328,674		350,083
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	307,612		307,612		297,890
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	462,712		462,712		473,263
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	626,525		626,525		107,761
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	53,046		53,046		60,977
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	26,642		26,642		27,496
Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	130,809		130,809		134,537
Stream interests
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	1,507,078		1,507,078		1,584,045
Revenue	98,732	115,921	308,863	325,688
Cost of sales	23,221	27,230	69,670	73,367
Depletion	32,576	41,922	106,745	113,263
Total segment gross profit	42,935	46,769	132,448	139,058
Stream interests | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	528,325		528,325		579,326
Revenue	46,861	64,031	152,938	158,679
Stream interests | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	328,674		328,674		350,083
Revenue	21,156	27,198	64,232	83,957
Stream interests | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	307,291		307,291		297,569
Revenue	13,257	8,679	38,633	26,149
Stream interests | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	238,596		238,596		249,147
Revenue	12,170	11,601	39,566	52,491
Stream interests | Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	104,192		104,192		107,920
Revenue	5,288	4,412	13,494	4,412
Royalty interests
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	1,577,302		1,577,302		859,707
Revenue	32,697	58,510	131,363	159,359
Production taxes	1,119	2,054	4,765	6,042
Depletion	5,063	8,596	22,623	26,394
Total segment gross profit	26,515	47,860	103,975	126,923
Royalty interests | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	620,035		620,035		412,419
Revenue	4,826	6,402	21,377	24,616
Royalty interests | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	321		321		321
Revenue		602	430	1,909
Royalty interests | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	224,116		224,116		224,116
Royalty interests | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	626,525		626,525		107,761
Revenue	11,413	27,080	52,616	64,903
Royalty interests | Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	53,046		53,046		60,977
Revenue	11,095	15,427	38,915	46,888
Royalty interests | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	26,642		26,642		27,496
Revenue	3,446	6,917	11,533	15,526
Royalty interests | Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	26,617		26,617		$ 26,617
Revenue	$ 1,917	$ 2,082	$ 6,492	$ 5,517