SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)	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	$ 2,863,440		$ 2,863,440		$ 2,083,608
Revenue	93,487	$ 74,110	265,660	$ 204,439
Cost of sales	17,921	10,542	51,960	23,452
Net revenue	75,566	63,568		180,987
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,048,572		1,048,572		1,074,779
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	829,314		829,314		653,019
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	597,060		597,060
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	121,269		121,269		131,742
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	104,785		104,785		110,286
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	71,146		71,146		12,760
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	44,488		44,488		50,119
Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	46,806		46,806		50,903
Royalty Interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	989,841		989,841		1,252,334
Revenue	30,048	44,392	97,053	137,746
Net revenue	30,048	44,392	97,053	137,746
Royalty Interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	230,170		230,170		251,688
Revenue	8,029	7,527	25,635	29,256
Net revenue	8,029	7,527	25,635	29,256
Royalty Interest | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	453,629		453,629		653,019
Royalty Interest | Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	121,269		121,269		131,742
Revenue	8,353	11,016	29,446	29,454
Net revenue	8,353	11,016	29,446	29,454
Royalty Interest | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	104,785		104,785		110,286
Revenue	8,522	10,975	27,220	32,639
Net revenue	8,522	10,975	27,220	32,639
Royalty Interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	719		719		12,760
Revenue	570	722	1,301	2,595
Net revenue	570	722	1,301	2,595
Royalty Interest | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	44,488		44,488		50,119
Revenue	2,834	2,466	7,610	6,390
Net revenue	2,834	2,466	7,610	6,390
Royalty Interest | Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	34,781		34,781		42,720
Revenue	1,740	11,686	5,841	37,412
Net revenue	1,740	11,686	5,841	37,412
Stream Interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,873,599		1,873,599		831,274
Revenue	63,439	29,718	168,607	66,693
Cost of sales	17,921	10,542	51,960	23,452
Net revenue	45,518	19,176	116,647	43,241
Stream Interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	818,402		818,402		823,091
Revenue	29,946	29,718	95,881	66,693
Cost of sales	11,095	10,542	37,084	23,452
Net revenue	18,851	$ 19,176	58,797	$ 43,241
Stream Interest | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	375,685		375,685
Revenue	15,730		32,163
Cost of sales	2,255		4,751
Net revenue	13,475		27,412
Stream Interest | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	597,060		597,060
Revenue	13,608		23,008
Cost of sales	3,787		6,619
Net revenue	9,821		16,389
Stream Interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	70,427		70,427
Revenue	4,155		17,555
Cost of sales	784		3,506
Net revenue	3,371		14,049
Stream Interest | Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	$ 12,025		$ 12,025		$ 8,183