STREAM AND ROYALTY INTERESTS, NET (Details) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2016 USD ($) oz	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Stream and royalty interests
Cost				$ 3,551,575	$ 2,647,976
Accumulated Depletion				(607,370)	(536,029)
Impairments				(96,118)	(28,339)
Net				2,848,087	2,083,608
Impairments of stream and royalty interests				96,118	28,339
Return of advance payment					10,000
Total impairments of stream and royalty interests and royalty receivables				98,588	31,335
Royalty receivables				17,990	37,681
Other
Stream and royalty interests
Net	$ 0
Impairments of stream and royalty interests				3,127	2,372
Phoenix Gold
Stream and royalty interests
Net	0
Impairments of stream and royalty interests				75,702
Wolverine
Stream and royalty interests
Net	0				5,300
Impairments of stream and royalty interests				5,307	25,967
Allowance for royalty receivables				$ (385)	2,996
Royalty receivables		$ 3,000
Wolverine | Minimum
Stream and royalty interests
Percentage of royalty interests acquired				0.00%
Wolverine | Maximum
Stream and royalty interests
Percentage of royalty interests acquired				9.445%
Inata
Stream and royalty interests
Net	0					$ 12,000
Impairments of stream and royalty interests				$ 11,982
Allowance for royalty receivables				$ 2,855
Inata | Avocet
Stream and royalty interests
Percentage of royalty interests acquired				2.50%
Royalty receivables				$ 2,800
Tulsequah
Stream and royalty interests
Net		0
Impairments of stream and royalty interests		600
Material properties net related to investments		10,000
Material properties net direct acquisition costs		600
Chieftain
Stream and royalty interests
Return of advance payment		$ 10,000
Production Stage Stream Interests
Stream and royalty interests
Cost				1,878,045
Accumulated Depletion				(122,064)
Net				1,755,981
Production Stage Stream Interests | Andacollo
Stream and royalty interests
Cost				388,182
Accumulated Depletion				(18,286)
Net				369,896
Production Stage Stream Interests | Mt. Milligan
Stream and royalty interests
Cost				783,046	783,046
Accumulated Depletion				(74,060)	(35,195)
Net				708,986	747,851
Production Stage Stream Interests | Pueblo Viejo
Stream and royalty interests
Cost				610,404
Accumulated Depletion				(21,902)
Net				588,502
Production Stage Stream Interests | Wassa and Prestea
Stream and royalty interests
Cost				96,413
Accumulated Depletion				(7,816)
Net				88,597
Production Stage Royalty Interests
Stream and royalty interests
Cost				881,873	1,129,230
Accumulated Depletion				(485,153)	(500,834)
Impairments				(18,605)	(27,586)
Net				378,115	600,810
Production Stage Royalty Interests | Voisey's Bay
Stream and royalty interests
Cost				205,724	150,138
Accumulated Depletion				(85,671)	(76,141)
Net				120,053	73,997
Production Stage Royalty Interests | Andacollo
Stream and royalty interests
Cost					272,998
Accumulated Depletion					(65,467)
Net					207,531
Production Stage Royalty Interests | Penasquito
Stream and royalty interests
Cost				99,172	99,172
Accumulated Depletion				(29,898)	(24,555)
Net				69,274	74,617
Production Stage Royalty Interests | Holt
Stream and royalty interests
Cost				34,612	34,612
Accumulated Depletion				(17,124)	(13,950)
Net				17,488	20,662
Production Stage Royalty Interests | Mulatos
Stream and royalty interests
Cost					48,092
Accumulated Depletion					(32,313)
Net					15,779
Production Stage Royalty Interests | Cortez
Stream and royalty interests
Cost				10,630	10,630
Accumulated Depletion				(10,000)	(9,933)
Net				630	697
Production Stage Royalty Interests | Robinson
Stream and royalty interests
Cost					17,825
Accumulated Depletion					(12,748)
Net					5,077
Production Stage Royalty Interests | Other
Stream and royalty interests
Cost				531,735	495,763
Accumulated Depletion				(342,460)	(265,727)
Impairments				(18,605)	(27,586)
Net				170,670	202,450
Production Stage Stream and Royalty Interests
Stream and royalty interests
Cost				2,759,918	1,912,276
Accumulated Depletion				(607,217)	(536,029)
Impairments				(18,605)	(27,586)
Net				2,134,096	1,348,661
Development Stage Royalty Interests
Stream and royalty interests
Cost				447,071	84,026
Impairments					(603)
Net				447,071	83,423
Development Stage Royalty Interests | Other
Stream and royalty interests
Cost				66,414	8,183
Impairments					(603)
Net				66,414	7,580
Development Stage Royalty Interests | Pascua Lama
Stream and royalty interests
Cost				380,657	75,843
Net				380,657	75,843
Development Stage Stream Interests
Stream and royalty interests
Cost				188,589	439,122
Accumulated Depletion				(153)
Impairments				(75,702)
Net				112,734	439,122
Development Stage Stream Interests | Other
Stream and royalty interests
Cost				87,883	67,017
Accumulated Depletion				(153)
Impairments				(75,702)
Net				12,028	67,017
Development Stage Stream Interests | Rainy River
Stream and royalty interests
Cost				100,706
Net				100,706
Development Stage Stream Interests | Pascua Lama
Stream and royalty interests
Cost					372,105
Net					372,105
Development Stage Stream and Royalty Interests
Stream and royalty interests
Cost				635,660	523,148
Accumulated Depletion				(153)
Impairments				(75,702)	(603)
Net				559,805	522,545
Exploration Stage Royalty Interest
Stream and royalty interests
Cost				155,997	212,552
Impairments				(1,811)	(150)
Net				$ 154,186	$ 212,402
Initial Royalty | RGLD Gold | Phoenix Gold | Rubicon Minerals Corporation
Stream and royalty interests
Percentage of royalty interests acquired				6.30%
Gold delivered (in ounces) | oz				135,000
Subsequent Royalty | RGLD Gold | Phoenix Gold | Rubicon Minerals Corporation
Stream and royalty interests
Percentage of royalty interests acquired				3.15%
Production Stage and Exploration Stage Royalty Interest
Stream and royalty interests
Impairments of stream and royalty interests			$ 1,800
Production Stage and Exploration Stage Royalty Interest | Other
Stream and royalty interests
Impairments of stream and royalty interests	$ 3,100