SEGMENT INFORMATION - Geographical (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($) segment	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Long Lived Assets and Pre-Tax Income by Geographical Information
Number of reportable segments | segment	2
Total stream and royalty interests, net	$ 3,059,885		$ 3,042,804
Revenue	193,436	$ 148,902
Cost of sales	24,506	21,751
Production taxes	1,761	1,449
Depletion	32,915	38,683
Segment gross profit	134,254	87,019
Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,282,819		1,253,170
Revenue	122,482	102,528
Cost of sales	24,506	21,751
Production taxes	0	0
Depletion	20,353	27,401
Segment gross profit	77,623	53,376
Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,777,066		1,789,634
Revenue	70,954	46,374
Cost of sales	0	0
Production taxes	1,761	1,449
Depletion	12,562	11,282
Segment gross profit	56,631	33,643
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,063,383		1,076,713
Canada | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	409,644		417,643
Revenue	53,230	44,705
Canada | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	653,739		659,070
Revenue	10,712	5,131
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	299,395		302,122
Dominican Republic | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	299,395		302,122
Revenue	28,751	17,760
Dominican Republic | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	231,285		237,349
Africa | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	230,964		237,028
Revenue	22,381	19,101
Africa | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	321		321
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	432,847		435,239
Chile | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	208,731		211,123
Revenue	12,744	11,689
Chile | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	224,116		224,116
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	822,355		827,277
United States | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0
United States | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	822,355		827,277
Revenue	31,006	24,079
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	32,191		33,800
Mexico | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0
Mexico | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	32,191		33,800
Revenue	17,071	10,768
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	18,723		19,265
Australia | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0
Australia | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	18,723		19,265
Revenue	7,956	4,975
Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	159,706		111,039
Rest of world | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	134,085		85,254
Revenue	5,376	9,273
Rest of world | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	25,621		$ 25,785
Revenue	$ 4,209	$ 1,421