STREAM AND ROYALTY INTERESTS, NET - Summary (Details) - USD ($) $ in Thousands		3 Months Ended
	May 21, 2025	Dec. 31, 2025	Sep. 30, 2025	Dec. 31, 2024
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			$ 6,141,743	$ 4,985,510
Accumulated Depletion			(2,039,512)	(1,942,706)
Net			4,102,231	3,042,804
Warintza Project Stream and Royalty
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Conditional funding from acquisition	$ 100,000
Forecast | Warintza Project Stream and Royalty
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Asset acquisition, consideration transferred		$ 200,000
Asset acquisition, cash paid for royalty and streaming agreements		100,000
Forecast | Warintza Project Stream and Royalty | Environmental Impact Milestone
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Conditional funding from acquisition		50,000
Forecast | Warintza Project Stream and Royalty | Security Milestone
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Conditional funding from acquisition		$ 50,000
Total production stage stream and royalty interests
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			4,780,315	3,767,113
Accumulated Depletion			(2,039,512)	(1,942,706)
Net			2,740,803	1,824,407
Total production stage stream interests
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			3,473,077	2,472,689
Accumulated Depletion			(1,307,259)	(1,246,349)
Net			2,165,818	1,226,340
Total production stage stream interests | Kansanshi
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			1,000,388
Accumulated Depletion			0
Net			1,000,388
Total production stage stream interests | Mount Milligan
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			790,635	790,635
Accumulated Depletion			(480,076)	(462,412)
Net			310,559	328,223
Total production stage stream interests | Pueblo Viejo
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			610,404	610,404
Accumulated Depletion			(315,400)	(308,283)
Net			295,004	302,121
Total production stage stream interests | Andacollo
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			388,182	388,182
Accumulated Depletion			(184,754)	(177,059)
Net			203,428	211,123
Total production stage stream interests | Khoemacau
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			265,911	265,911
Accumulated Depletion			(69,350)	(58,043)
Net			196,561	207,868
Total production stage stream interests | Rainy River
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			175,727	175,727
Accumulated Depletion			(94,146)	(86,307)
Net			81,581	89,420
Total production stage stream interests | Other
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			241,830	241,830
Accumulated Depletion			(163,533)	(154,245)
Net			78,297	87,585
Total production stage royalty interests
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			1,307,238	1,294,424
Accumulated Depletion			(732,253)	(696,357)
Net			574,985	598,067
Total production stage royalty interests | Other
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			519,720	519,491
Accumulated Depletion			(426,680)	(418,648)
Net			93,040	100,843
Total production stage royalty interests | Cortez (Legacy Zone and CC Zone)
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			366,435	353,850
Accumulated Depletion			(96,350)	(81,845)
Net			270,085	272,005
Total production stage royalty interests | Voisey's Bay
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			205,724	205,724
Accumulated Depletion			(129,985)	(124,526)
Net			75,739	81,198
Total production stage royalty interests | Red Chris
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			116,187	116,187
Accumulated Depletion			(9,033)	(5,966)
Net			107,154	110,221
Total production stage royalty interests | Peñasquito
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			99,172	99,172
Accumulated Depletion			(70,205)	(65,372)
Net			28,967	33,800
Total development stage stream and royalty interests
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			159,385	166,387
Net			159,385	166,387
Development stage stream interests | Ilovica
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			12,038	12,038
Net			12,038	12,038
Development stage royalty interests | Other
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			21,133	21,133
Net			21,133	21,133
Development stage royalty interests | Cactus
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			48,126	55,128
Net			48,126	55,128
Development stage royalty interests | Back River
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			42,948	42,948
Net			42,948	42,948
Development stage royalty interests | La Fortuna
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			35,140	35,140
Net			35,140	35,140
Total exploration stage stream and royalty interests
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			1,202,043	1,052,010
Net			1,202,043	1,052,010
Exploration stage stream interests | Warintza
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			95,252
Net			95,252
Exploration stage stream interests | Xavantina
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			64,834	14,792
Net			64,834	14,792
Exploration stage royalty interests | Other
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			132,762	115,438
Net			132,762	115,438
Exploration stage royalty interests | Cortez (Legacy Zone and CC Zone)
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			443,894	456,479
Net			443,894	456,479
Exploration stage royalty interests | Red Chris
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			48,895	48,895
Net			48,895	48,895
Exploration stage royalty interests | Great Bear
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			209,106	209,106
Net			209,106	209,106
Exploration stage royalty interests | Pascua-Lama
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			177,690	177,690
Net			177,690	177,690
Exploration stage royalty interests | Côté
Oil and Gas, Full Cost Method, Capitalized Cost Excluded from Amortization [Line Items]
Cost			29,610	29,610
Net			$ 29,610	$ 29,610