SEGMENT INFORMATION (Details) $ in Thousands	6 Months Ended		12 Months Ended
	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Long Lived Assets and Pre-Tax Income by Geographical Information
Number of reportable segments | segment	2
Stream and royalty interest	$ 2,443,752		$ 2,262,158	$ 2,318,913
Revenue	342,952	$ 305,240	615,856	498,819	$ 423,056
Cost of sales	52,329	46,760	92,898	83,890	77,535
Production taxes	4,412	$ 2,756	6,743	3,824	4,112
Depletion	99,470		183,213	175,047	162,856
Total segment gross profit	186,741		333,002	236,058	178,553
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	991,745		876,759	892,587
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	350,083		366,698	406,469
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	473,263		480,720	501,583
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	297,890		291,433	215,784
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	107,761		112,817	159,445
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	60,977		66,867	75,951
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	27,496		28,117	30,006
Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	134,537		38,747	37,088
Stream interests
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	1,584,045		1,550,664	1,614,363
Revenue	226,551		423,989	359,868	305,824
Cost of sales	52,329		92,898	83,890	77,535
Depletion	82,603		150,594	144,678	127,770
Total segment gross profit	91,619		180,497	131,300	100,519
Stream interests | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	579,326		624,212	702,732
Revenue	115,544		190,537	158,736	123,152
Stream interests | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	350,083		366,698	406,469
Revenue	52,958		115,583	96,978	82,844
Stream interests | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	249,147		256,604	277,661
Revenue	28,075		82,164	74,219	69,264
Stream interests | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	297,569		291,112	215,463
Revenue	22,228		35,705	29,935	30,564
Stream interests | Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	107,920		12,038	12,038
Revenue	7,746
Royalty interests
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	859,707		711,494	704,550
Revenue	116,401		191,867	138,951	117,232
Production taxes	4,412		6,743	3,824	4,112
Depletion	16,867		32,619	30,369	35,086
Total segment gross profit	95,122		152,505	104,758	78,034
Royalty interests | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	412,419		252,547	189,855
Revenue	13,756		31,671	30,524	32,602
Royalty interests | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	224,116		224,116	223,922
Royalty interests | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	321		321	321
Revenue	1,107		2,801	2,575	1,416
Royalty interests | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	107,761		112,817	159,445
Revenue	54,046		68,611	48,692	34,845
Royalty interests | Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	60,977		66,867	75,951
Revenue	31,858		58,212	32,731	27,224
Royalty interests | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	27,496		28,117	30,006
Revenue	11,174		21,466	15,252	12,806
Royalty interests | Rest of world
Long Lived Assets and Pre-Tax Income by Geographical Information
Stream and royalty interest	26,617		26,709	25,050
Revenue	$ 4,460		$ 9,106	$ 9,177	$ 8,339