EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
EARNINGS PER SHARE ("EPS")
Net income attributable to Royal Gold common stockholders	$ 59,889	$ 41,321	$ 166,828	$ 111,774
Weighted-average shares for basic EPS	65,546,938	65,495,907	65,542,326	65,480,759
Effect of other dilutive securities (in shares)	72,303	115,660	83,639	132,647
Weighted-average shares for diluted EPS	65,619,241	65,611,567	65,625,965	65,613,406
Basic EPS (in dollars per share)	$ 0.91	$ 0.63	$ 2.55	$ 1.70
Diluted EPS (in dollars per share)	$ 0.91	$ 0.63	$ 2.54	$ 1.70