EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
EARNINGS PER SHARE ("EPS")
Net income (loss) available to Royal Gold common stockholders	$ 23,586	$ (14,765)	$ 38,596	$ 13,864
Weighted-average shares for basic EPS	65,395,457	65,306,766	65,385,161	65,271,131
Effect of other dilutive securities (in shares)	77,943		100,262	189,299
Weighted-average shares for diluted EPS	65,473,400	65,306,766	65,485,423	65,460,430
Basic earnings (loss) per share (in dollars per share)	$ 0.36	$ (0.23)	$ 0.59	$ 0.21
Diluted earnings (loss) per share (in dollars per share)	0.36	$ (0.23)	0.59	$ 0.21
Initial conversion price (in dollars per share)	$ 102.29		$ 102.29