ACQUISITIONS (Details) $ / shares in Units, shares in Millions, km in Millions									1 Months Ended	12 Months Ended
	Sep. 19, 2016 USD ($)	Dec. 30, 2015 USD ($)	Sep. 29, 2015 USD ($) oz	Jul. 28, 2015 USD ($) oz $ / shares shares	Jul. 20, 2015 USD ($) oz	Jul. 09, 2015 USD ($) km oz	Jan. 08, 2015 USD ($)	Sep. 30, 2014 USD ($)	Nov. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Acquisition of Royalty Interest in Mineral Properties
Carrying value										$ 3,624,495,000	$ 3,551,575,000
Funds received for royalty termination											345,000,000
Peak Gold
Acquisition of Royalty Interest in Mineral Properties
Consideration paid								$ 6,000,000
Payments to acquire interest in joint venture							$ 5,000,000			$ 18,000,000	$ 5,700,000
Joint venture ownership interest (as a percent)										29.50%	11.00%
Maximum ownership interest (as a percent)							40.00%
Maximum contribution amount							$ 30,000,000
Minimum interest required to manage (as a percent)							40.00%
Joint venture net value										$ 45,700,000
NSR Royalty Option 1 | Peak Gold
Acquisition of Royalty Interest in Mineral Properties
Net Smelter Return (“NSR”) (as a percent)								2.00%
NSR Royalty Option 2 | Peak Gold
Acquisition of Royalty Interest in Mineral Properties
Net Smelter Return (“NSR”) (as a percent)								3.00%
Contango | Peak Gold
Acquisition of Royalty Interest in Mineral Properties
Joint venture ownership interest (as a percent)							100.00%
Cortez
Acquisition of Royalty Interest in Mineral Properties
NVR (as a percent)	3.75%
Consideration paid	$ 70,000,000
Cortez Crossroad Claim
Acquisition of Royalty Interest in Mineral Properties
NVR (as a percent)	4.52%
GSR royalty (as a percent)	5.00%
Consideration paid	$ 59,800,000
Cortez, excluding the Crossroad Claims
Acquisition of Royalty Interest in Mineral Properties
NVR (as a percent)	4.91%
GSR royalty (as a percent)	5.71%
Consideration paid	$ 10,200,000
Pueblo Viejo
Acquisition of Royalty Interest in Mineral Properties
Consideration paid			$ 610,000,000
Purchase price per ounce of silver (as a percent)			60.00%
Pueblo Viejo | Initial Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)			7.50%
Gold delivered (in ounces) | oz			990,000
Silver royalty interests acquired (as a percent)			75.00%
Minimum silver recovery (as a percent)			70.00%
Silver delivered (in ounces) | oz			50,000,000
Pueblo Viejo | Subsequent Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)			3.75%
Silver royalty interests acquired (as a percent)			37.50%
Pueblo Viejo | First Condition
Acquisition of Royalty Interest in Mineral Properties
Gold delivered (in ounces) | oz			550,000
Silver delivered (in ounces) | oz			23,100,000
Purchase price per ounce of silver (as a percent)			30.00%
Pueblo Viejo | Second Condition
Acquisition of Royalty Interest in Mineral Properties
Purchase price per ounce of gold (as a percent)			60.00%
Pueblo Viejo | Barrick
Acquisition of Royalty Interest in Mineral Properties
Ownership interest (as a percent)			60.00%
Wassa and Prestea
Acquisition of Royalty Interest in Mineral Properties
Consideration paid		$ 15,000,000		$ 130,000,000
Carrying value		$ 145,000,000
Cash paid for acquisition of royalty interests										55,000,000	$ 95,000,000
Remaining consideration payable										0
Wassa and Prestea | Initial Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)				9.25%
Gold delivered (in ounces) | oz				240,000
Wassa and Prestea | Subsequent Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)				10.50%
Wassa and Prestea | First Condition
Acquisition of Royalty Interest in Mineral Properties
Purchase price per ounce of gold (as a percent)				20.00%
Wassa and Prestea | Second Condition
Acquisition of Royalty Interest in Mineral Properties
Purchase price per ounce of gold (as a percent)				30.00%
Wassa and Prestea | Subsequent Two Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)				5.50%
Rainy River
Acquisition of Royalty Interest in Mineral Properties
Consideration paid					$ 175,000,000
Cash paid for acquisition of royalty interests					$ 100,000,000				$ 75,000,000
Remaining consideration payable										0
Rainy River | Initial Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)					6.50%
Gold delivered (in ounces) | oz					230,000
Silver royalty interests acquired (as a percent)					60.00%
Silver delivered (in ounces) | oz					3,100,000
Rainy River | Subsequent Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)					3.25%
Purchase price per ounce of gold (as a percent)					25.00%
Silver royalty interests acquired (as a percent)					30.00%
Carmen de Andacollo
Acquisition of Royalty Interest in Mineral Properties
Consideration paid						$ 525,000,000
Royalty interests acquired (as a percent)						89.00%
Purchase price per ounce of gold (as a percent)						15.00%
Carrying value										$ 388,200,000
Area of mining to be eligible for concessions | km						1.5
Carmen de Andacollo | Initial Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)						100.00%
Gold delivered (in ounces) | oz						900,000
Carmen de Andacollo | Subsequent Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)						50.00%
Carmen de Andacollo | Teck
Acquisition of Royalty Interest in Mineral Properties
Ownership interest (as a percent)						90.00%
Golden Star
Acquisition of Royalty Interest in Mineral Properties
Gross loans				$ 20,000,000
Term of loan				4 years
Common stock that can be purchased by warrants (in shares) | shares				5
Grant date fair value of warrants				$ 800,000
Quarterly interest rate based on average gold rate				62.50%
Denominator used in calculation of quarterly interest rate				$ 10,000
Term of warrants				4 years
Exercise price of warrants | $ / shares				$ 0.27
Golden Star | Maximum
Acquisition of Royalty Interest in Mineral Properties
Interest rate (as a percent)				$ 11.5
Termination Agreement | Carmen de Andacollo
Acquisition of Royalty Interest in Mineral Properties
Carrying value						$ 207,500,000
Funds received for royalty termination						345,000,000
Gain on contract termination						$ 0
Termination Agreement | Carmen de Andacollo | Initial Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)						75.00%
Gold delivered (in ounces) | oz						910,000
Termination Agreement | Carmen de Andacollo | Subsequent Royalty
Acquisition of Royalty Interest in Mineral Properties
Royalty interests acquired (as a percent)						50.00%