SEGMENT INFORMATION - Geographical (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) segment	Sep. 30, 2024 USD ($)	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	$ 4,102,231		$ 4,102,231		$ 3,042,804
Revenue	252,068	$ 193,837	655,148	$ 516,835
Cost of sales	31,392	27,192	80,077	73,116
Production taxes	2,418	1,520	6,381	4,550
Depletion	32,821	36,091	96,807	110,433
Segment gross profit	185,437	129,034	471,883	328,736
Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	2,337,942		2,337,942		1,253,170
Revenue	166,081	133,052	421,754	358,531
Cost of sales	31,392	27,192	80,077	73,116
Production taxes	0	0	0	0
Depletion	21,287	26,674	60,910	80,199
Segment gross profit	113,402	79,186	280,767	205,216
Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,764,289		1,764,289		1,789,634
Revenue	85,987	60,785	233,394	158,304
Cost of sales	0	0	0	0
Production taxes	2,418	1,520	6,381	4,550
Depletion	11,534	9,417	35,897	30,234
Segment gross profit	72,035	49,848	191,116	123,520
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,220,194		1,220,194		237,349
Africa | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,219,873		1,219,873		237,028
Revenue	27,288	19,973	70,055	59,470
Africa | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	321		321		321
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	1,052,771		1,052,771		1,076,713
Canada | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	392,140		392,140		417,643
Revenue	82,364	66,372	208,344	173,737
Canada | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	660,631		660,631		659,070
Revenue	14,439	5,269	32,070	13,435
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	295,004		295,004		302,122
Dominican Republic | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	295,004		295,004		302,122
Revenue	28,140	26,585	82,509	64,147
Dominican Republic | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	427,544		427,544		435,239
Chile | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	203,428		203,428		211,123
Revenue	23,022	9,652	45,255	31,949
Chile | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	224,116		224,116		224,116
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	801,697		801,697		827,277
United States | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
United States | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	801,697		801,697		827,277
Revenue	37,080	34,131	105,478	83,484
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	28,967		28,967		33,800
Mexico | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Mexico | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	28,967		28,967		33,800
Revenue	19,957	10,853	54,659	34,509
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	18,181		18,181		19,265
Australia | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	0		0		0
Australia | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	18,181		18,181		19,265
Revenue	10,589	7,476	28,362	19,498
Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	257,873		257,873		111,039
Rest of world | Stream interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	227,497		227,497		85,254
Revenue	5,267	10,470	15,591	29,228
Rest of world | Royalty interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total stream and royalty interests, net	30,376		30,376		$ 25,785
Revenue	$ 3,922	$ 3,056	$ 12,825	$ 7,378