EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
EARNINGS PER SHARE ("EPS")
Net income (loss) available to Royal Gold common stockholders	$ 70,453	$ 15,008
Weighted-average shares for basic EPS	65,465,611	65,374,866
Effect of other dilutive securities (in shares)	150,315	122,293
Weighted-average shares for diluted EPS	65,615,926	65,497,159
Basic earnings per share (in dollars per share)	$ 1.07	$ 0.23
Diluted earnings per share (in dollars per share)	$ 1.07	$ 0.23