STREAM AND ROYALTY INTERESTS, NET - Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020
Cost	$ 3,521,808	$ 3,553,950
Accumulated Depletion	(1,279,494)	(1,233,696)
Impairments		(1,341)
Net	2,242,314	2,318,913
Wassa and Prestea
Net	75,900
Total production stage stream and royalty interests
Cost	3,017,116	3,018,837
Accumulated Depletion	(1,279,494)	(1,233,696)
Impairments		(1,341)
Net	1,737,622	1,783,800
Production stage stream interests
Cost	2,111,423	2,111,423
Accumulated Depletion	(684,732)	(645,705)
Net	1,426,691	1,465,718
Production stage stream interests | Mount Milligan
Cost	790,635	790,635
Accumulated Depletion	(251,423)	(236,352)
Net	539,212	554,283
Production stage stream interests | Pueblo Viejo
Cost	610,404	610,404
Accumulated Depletion	(215,824)	(203,935)
Net	394,580	406,469
Production stage stream interests | Andacollo
Cost	388,182	388,182
Accumulated Depletion	(116,328)	(110,521)
Net	271,854	277,661
Production stage stream interests | Rainy River
Cost	175,727	175,727
Accumulated Depletion	(30,480)	(27,278)
Net	145,247	148,449
Production stage stream interests | Wassa and Prestea
Cost	146,475	146,475
Accumulated Depletion	(70,677)	(67,619)
Net	75,798	78,856
Production stage royalty interests
Cost	905,693	907,414
Accumulated Depletion	(594,762)	(587,991)
Impairments		(1,341)
Net	310,931	318,082
Production stage royalty interests | Voisey's Bay
Cost	205,724	205,724
Accumulated Depletion	(103,271)	(101,381)
Net	102,453	104,343
Production stage royalty interests | Penasquito
Cost	99,172	99,172
Accumulated Depletion	(45,741)	(44,614)
Net	53,431	54,558
Production stage royalty interests | Holt
Cost	34,612	34,612
Accumulated Depletion	(23,867)	(23,851)
Net	10,745	10,761
Production stage royalty interests | Cortez
Cost	80,681	80,681
Accumulated Depletion	(15,657)	(15,065)
Net	65,024	65,616
Production stage royalty interests | Other
Cost	485,504	487,225
Accumulated Depletion	(406,226)	(403,080)
Impairments		(1,341)
Net	79,278	82,804
Total development stage stream and royalty interests
Cost	230,707	219,597
Net	230,707	219,597
Total development stage stream and royalty interests | Other
Cost		70,952
Net		70,952
Development stage stream interests | Khoemacau
Cost	147,718	136,608
Net	147,718	136,608
Development stage stream interests | Other
Cost	12,037	12,037
Net	12,037	12,037
Development stage royalty interests
Cost		70,952
Net		70,952
Development stage royalty interests | Other
Cost	70,952
Net	70,952
Exploration stage royalty interests
Cost	273,985	315,516
Net	273,985	315,516
Exploration stage royalty interests | Pascua-Lama
Cost	177,690	177,690
Net	177,690	177,690
Exploration stage royalty interests | Other
Cost	96,295	137,826
Net	$ 96,295	$ 137,826