MAJOR SOURCES OF REVENUE (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
MAJOR SOURCES OF REVENUE
Minimum percentage required for qualifying as major operator	10.00%
Teck | Royalty revenue | Concentration of risk by operator
Major sources of revenue
Revenue	$ 48,777	$ 82,272	$ 64,075
Percentage of total revenue	20.60%	28.40%	24.40%
Goldcorp, Inc. | Royalty revenue | Concentration of risk by operator
Major sources of revenue
Revenue	32,339	32,461	31,407
Percentage of total revenue	13.60%	11.20%	11.90%
Thompson Creek | Royalty revenue | Concentration of risk by operator
Major sources of revenue
Revenue	27,209
Percentage of total revenue	11.50%
Vale Newfoundland & Labrador Limited | Royalty revenue | Concentration of risk by operator
Major sources of revenue
Revenue	$ 25,128	$ 32,517	$ 36,030
Percentage of total revenue	10.60%	11.20%	13.70%