EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
EARNINGS PER SHARE ("EPS")
Net income attributable to Royal Gold common stockholders	$ 302,532	$ 199,343	$ 93,825
Weighted-average shares for basic EPS	65,546,400	65,523,024	65,394,627
Effect of other dilutive securities	81,191	120,366	110,908
Weighted-average shares for diluted EPS	65,627,591	65,643,390	65,505,535
Basic EPS	$ 4.61	$ 3.04	$ 1.43
Diluted EPS	$ 4.60	$ 3.03	$ 1.43