EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Net income attributable to Royal Gold common stockholders	$ 96,242	$ 49,337	$ 224,615	$ 176,661
Weighted-average shares for basic EPS (in shares)	65,670,381	65,619,406	65,652,934	65,606,681
Effect of other dilutive securities (in shares)	124,633	137,670	114,734	136,433
Weighted-average shares for diluted EPS (in shares)	65,795,014	65,757,076	65,767,668	65,743,114
Basic EPS (in dollars per share)	$ 1.46	$ 0.75	$ 3.41	$ 2.69
Diluted EPS (in dollars per share)	$ 1.46	$ 0.75	$ 3.41	$ 2.68