EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
EARNINGS PER SHARE ("EPS")
Net income (loss) available to Royal Gold common stockholders	$ 28,631	$ 29,787
Weighted-average shares for basic EPS	65,235,496	65,116,686
Effect of other dilutive securities (in shares)	169,184	164,218
Weighted-average shares for diluted EPS	65,404,680	65,280,904
Basic earnings per share (in dollars per share)	$ 0.44	$ 0.46
Diluted earnings per share (in dollars per share)	0.44	$ 0.46
Initial conversion price (in dollars per share)	$ 102.91