REVENUE - Metal 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 \| Gold
Disaggregation of Revenue
Revenue	77,502	65,511
Stream interests \| Silver
Disaggregation of Revenue
Revenue	11,439	12,805
Stream interests \| Copper
Disaggregation of Revenue
Revenue	16,310	17,030
Royalty interests
Disaggregation of Revenue
Revenue	57,104	47,243
Royalty interests \| Gold
Disaggregation of Revenue
Revenue	37,917	31,245
Royalty interests \| Silver
Disaggregation of Revenue
Revenue	4,317	4,208
Royalty interests \| Copper
Disaggregation of Revenue
Revenue	6,705	4,015
Royalty interests \| Other
Disaggregation of Revenue
Revenue	$ 8,165	$ 7,775

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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+ Details