SEGMENT INFORMATION (Details)	3 Months Ended		6 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Jun. 30, 2011
Canada
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	28.00%	16.00%	24.00%	13.00%
Royalty Interests in Mineral Property, net (as a percent)	41.00%		41.00%		36.00%
Chile
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	25.00%	21.00%	26.00%	20.00%
Royalty Interests in Mineral Property, net (as a percent)	37.00%		37.00%		40.00%
Mexico
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	19.00%	19.00%	18.00%	16.00%
Royalty Interests in Mineral Property, net (as a percent)	10.00%		10.00%		11.00%
United States
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	16.00%	31.00%	20.00%	29.00%
Royalty Interests in Mineral Property, net (as a percent)	3.00%		3.00%		3.00%
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%	5.00%	6.00%
Royalty Interests in Mineral Property, net (as a percent)	4.00%		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%	6.00%	4.00%	13.00%
Royalty Interests in Mineral Property, net (as a percent)	1.00%		1.00%		2.00%
Other Countries
Geographic distribution of royalty revenue and long-lived assets (royalty interests in mineral properties, net)
Royalty Revenue (as a percent)	3.00%	2.00%	3.00%	3.00%
Royalty Interests in Mineral Property, net (as a percent)	4.00%		4.00%		3.00%