QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
QUARTERLY RESULTS OF OPERATIONS (UNAUDITED)
Revenue	$ 73,579	$ 74,110	$ 61,304	$ 69,026	$ 70,142	$ 57,748	$ 52,785	$ 56,487	$ 278,019	$ 237,162	$ 289,224
Operating income (loss)	27,568	32,150	(2,022)	29,539	31,452	28,614	22,916	25,738	87,235	108,720	171,167
Net income (loss) attributable to Royal Gold Stockholders	$ 14,819	$ 25,014	$ (6,548)	$ 18,680	$ 16,636	$ 20,143	$ 10,667	$ 15,195	$ 51,965	$ 62,641	$ 69,153
Basic earnings (loss) per share (in dollars per share)	$ 0.23	$ 0.38	$ (0.10)	$ 0.29	$ 0.26	$ 0.31	$ 0.16	$ 0.23	$ 0.80	$ 0.96	$ 1.09
Diluted earnings (loss) per share (in dollars per share)	$ 0.23	$ 0.38	$ (0.10)	$ 0.29	$ 0.26	$ 0.31	$ 0.16	$ 0.23	$ 0.80	$ 0.96	$ 1.09