SEGMENT INFORMATION (Details)	3 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2011
Chile
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	27.00%	19.00%
Royalty Interests in Mineral Property, net (as a percent)	40.00%		40.00%
United States
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	24.00%	26.00%
Royalty Interests in Mineral Property, net (as a percent)	3.00%		3.00%
Canada
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	20.00%	9.00%
Royalty Interests in Mineral Property, net (as a percent)	36.00%		36.00%
Mexico
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	17.00%	13.00%
Royalty Interests in Mineral Property, net (as a percent)	11.00%		11.00%
Australia
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	6.00%	7.00%
Royalty Interests in Mineral Property, net (as a percent)	4.00%		5.00%
Africa
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	4.00%	23.00%
Royalty Interests in Mineral Property, net (as a percent)	2.00%		2.00%
Other Countries
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	2.00%	3.00%
Royalty Interests in Mineral Property, net (as a percent)	4.00%		3.00%