MAJOR SOURCES OF REVENUE (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009
MAJOR SOURCES OF REVENUE
Minimum percentage required for qualifying as major operator (greater than, as a percent)	10.00%
Teck
Major sources of revenue
Royalty revenue	$ 43,604
Percentage of total royalty revenue (as a percent)	20.10%
Vale Inco Ltd.
Major sources of revenue
Royalty revenue	32,677
Percentage of total royalty revenue (as a percent)	15.10%
Barrick Gold
Major sources of revenue
Royalty revenue	26,843	30,624	22,200
Percentage of total royalty revenue (as a percent)	12.40%	22.40%	30.10%
Goldcorp, Inc.
Major sources of revenue
Royalty revenue	$ 23,094
Percentage of total royalty revenue (as a percent)	10.70%