SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) segment	Dec. 31, 2014 USD ($)	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	$ 2,996,421		$ 2,996,421		$ 2,083,608
Revenue	98,118	$ 61,304	172,173	$ 130,330
Cost of sales	22,572	6,236	34,038	12,910
Net revenue	75,546	55,068	138,135	117,420
Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,144,019		1,144,019		1,074,779
Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	835,297		835,297		653,019
Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	604,789		604,789
Mexico
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	124,192		124,192		131,742
United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	106,893		106,893		110,286
Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	46,667		46,667		50,119
Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	84,325		84,325		12,760
Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	50,239		50,239		50,903
Royalty Interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,022,881		1,022,881		1,252,334
Revenue	30,806	43,986	67,005	93,355
Net revenue	30,806	43,986	67,005	93,355
Royalty Interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	240,500		240,500		251,688
Revenue	7,206	10,403	17,607	21,730
Net revenue	7,206	10,403	17,607	21,730
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	124,192		124,192		131,742
Revenue	10,287	8,435	21,092	18,439
Net revenue	10,287	8,435	21,092	18,439
Royalty Interest | United States
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	106,893		106,893		110,286
Revenue	8,484	10,482	18,697	21,664
Net revenue	8,484	10,482	18,697	21,664
Royalty Interest | Australia
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	46,667		46,667		50,119
Revenue	2,325	2,031	4,776	3,924
Net revenue	2,325	2,031	4,776	3,924
Royalty Interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	12,727		12,727		12,760
Revenue	474	562	731	1,874
Net revenue	474	562	731	1,874
Royalty Interest | Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	38,273		38,273		42,720
Revenue	2,030	12,073	4,102	25,724
Net revenue	2,030	12,073	4,102	25,724
Stream Interest
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	1,973,540		1,973,540		831,274
Revenue	67,312	17,318	105,168	36,975
Cost of sales	22,572	6,236	34,038	12,910
Net revenue	44,740	11,082	71,130	24,065
Stream Interest | Canada
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	903,519		903,519		823,091
Revenue	42,418	17,318	65,935	36,975
Cost of sales	16,860	6,236	25,988	12,910
Net revenue	25,558	$ 11,082	39,947	$ 24,065
Stream Interest | Chile
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	381,668		381,668
Revenue	5,718		16,433
Cost of sales	892		2,496
Net revenue	4,826		13,937
Stream Interest | Dominican Republic
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	604,789		604,789
Revenue	9,400		9,400
Cost of sales	2,832		2,832
Net revenue	6,568		6,568
Stream Interest | Africa
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	71,598		71,598
Revenue	9,776		13,400
Cost of sales	1,988		2,722
Net revenue	7,788		10,678
Stream Interest | Other.
Long Lived Assets and Pre-Tax Income by Geographical Information
Total royalty and stream interest, net	$ 11,966		$ 11,966		$ 8,183