EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Earnings Per Share [Abstract]
Net income attributable to Royal Gold common stockholders	$ 126,824	$ 96,242	$ 372,670	$ 224,615
Weighted-average shares for basic EPS (in shares)	65,761,896	65,670,381	65,738,696	65,652,934
Effect of other dilutive securities (in shares)	69,445	124,633	75,986	114,734
Weighted-average shares for diluted EPS (in shares)	65,831,341	65,795,014	65,814,682	65,767,668
Basic EPS (in dollars per share)	$ 1.92	$ 1.46	$ 5.66	$ 3.41
Diluted EPS (in dollars per share)	$ 1.92	$ 1.46	$ 5.65	$ 3.41