EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
EARNINGS PER SHARE ("EPS")
Net (loss) income attributable to Royal Gold stockholders	$ (14,765)	$ 28,062	$ 13,864	$ 57,850
Weighted-average shares for basic EPS	65,306,766	65,149,518	65,271,131	65,133,102
Effect of other dilutive securities (in shares)		103,691	189,299	131,035
Weighted-average shares for diluted EPS	65,306,766	65,253,209	65,460,430	65,264,137
Basic (loss) earnings per share (in dollars per share)	$ (0.23)	$ 0.43	$ 0.21	$ 0.89
Diluted (loss) earnings per share (in dollars per share)	(0.23)	$ 0.43	0.21	$ 0.88
Initial conversion price (in dollars per share)	$ 102.79		$ 102.79