SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS (Details)	12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED ACCOUNTING PRONOUNCEMENTS
Maximum original maturity period of highly liquid investments (in months)	3
Percentage of revenue recognized pursuant to the Robinson royalty agreement (as a percent)	3.00%
Minimum specified future date of final assay and market metal prices to compute final true-up sales price payments to Quadra by third-party smelter (in months)	1
Maximum specified future date of final assay and market metal prices to compute final true-up sales price payments to Quadra by third-party smelter (in months)	3
Minimum period for concentrate to arrive at the third-party smelter (in months)	4
Maximum period for concentrate to arrive at the third-party smelter (in months)	5
United States
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	24.00%	40.00%	56.00%
Royalty Interests in Mineral Property, net (as a percent)	3.00%	5.00%	13.00%
Chile
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	21.00%	4.00%	1.00%
Royalty Interests in Mineral Property, net (as a percent)	40.00%	42.00%	6.00%
Canada
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	19.00%	4.00%	2.00%
Royalty Interests in Mineral Property, net (as a percent)	36.00%	27.00%	19.00%
Mexico
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	18.00%	15.00%	15.00%
Royalty Interests in Mineral Property, net (as a percent)	11.00%	13.00%	45.00%
Africa
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	9.00%	29.00%	21.00%
Royalty Interests in Mineral Property, net (as a percent)	2.00%	2.00%	8.00%
Australia
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	5.00%	5.00%	2.00%
Royalty Interests in Mineral Property, net (as a percent)	5.00%	6.00%	6.00%
Other
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	4.00%	3.00%	3.00%
Royalty Interests in Mineral Property, net (as a percent)	3.00%	5.00%	3.00%