SEGMENT INFORMATION - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
SEGMENT INFORMATION
Total segment gross profit	$ 333,002	$ 236,058	$ 178,553
Costs and expenses
General and administrative expenses	28,387	30,195	30,488
Exploration costs	563	5,190	7,158
Depreciation	356	387	200
Impairment of royalty interests		1,341
Total costs and expenses	29,306	37,113	37,846
Gain on sale of Peak Gold JV interest	33,906
Operating income	337,602	198,945	140,707
Fair value changes in equity securities	6,017	1,418	(6,800)
Interest and other income	2,443	2,046	2,320
Interest and other expense	(6,419)	(9,813)	(29,650)
Income before income taxes	$ 339,643	$ 192,596	$ 106,577