SEGMENT INFORMATION - Reconciliation (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
SEGMENT INFORMATION
Total segment gross profit	$ 186,741		$ 333,002	$ 236,058	$ 178,553
Costs and expenses
General and administrative expenses	15,163	$ 14,244	28,387	30,195	30,488
Exploration costs		563	563	5,190	7,158
Depreciation	215		356	387	200
Impairment of royalty interests				1,341
Gain on sale of Peak Gold JV interest		33,906	33,906
Total costs and expenses	15,378		29,306	37,113	37,846
Operating income	171,363	180,578	337,602	198,945	140,707
Fair value changes in equity securities	(1,350)	2,158	6,017	1,418	(6,800)
Interest and other income	1,610	1,034	2,443	2,046	2,320
Interest and other expense	(2,787)	(3,454)	(6,419)	(9,813)	(29,650)
Income before income taxes	$ 168,836	$ 180,316	$ 339,643	$ 192,596	$ 106,577