SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2015 USD ($) segment	Sep. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)
Long Lived Assets and Pre-Tax Income by Geographical Information
Number of reportable segments | segment	2
Total royalty and stream interest, net	$ 3,012,952		$ 2,083,608
Revenue	74,056	$ 69,026
Cost of sales	11,466	6,674
Net Revenue	62,590	62,352
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,162,278		1,074,779
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	837,595		653,019
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	610,367
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	127,962		131,742
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	109,772		110,286
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	48,330		50,119
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	67,939		12,760
Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	48,709		50,903
Royalty Interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,038,176		1,252,334
Revenue	36,199	49,369
Net Revenue	36,199	49,369
Royalty Interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	245,229		251,688
Revenue	10,401	11,326
Net Revenue	10,401	11,326
Royalty Interest | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	453,629		653,019
Revenue		11,233
Net Revenue		11,233
Royalty Interest | Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	127,962		131,742
Revenue	10,805	10,004
Net Revenue	10,805	10,004
Royalty Interest | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	109,772		110,286
Revenue	10,213	11,183
Net Revenue	10,213	11,183
Royalty Interest | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	48,330		50,119
Revenue	2,451	1,892
Net Revenue	2,451	1,892
Royalty Interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	12,748		12,760
Revenue	257	1,311
Net Revenue	257	1,311
Royalty Interest | Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	40,506		42,720
Revenue	2,072	2,420
Net Revenue	2,072	2,420
Stream Interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,974,776		831,274
Revenue	37,857
Cost of sales	11,466
Net Revenue	26,391
Stream Interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	917,049		823,091
Revenue	23,518	19,657
Cost of sales	9,128	6,674
Net Revenue	14,390	$ 12,983
Stream Interest | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	383,966
Revenue	10,715
Cost of sales	1,604
Net Revenue	9,111
Stream Interest | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	610,367
Stream Interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	55,191
Revenue	3,624
Cost of sales	734
Net Revenue	2,890
Stream Interest | Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	$ 8,203		$ 8,183