QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
QUARTERLY RESULTS OF OPERATIONS (UNAUDITED)
Revenue	$ 94,129	$ 93,487	$ 98,118	$ 74,056	$ 73,579	$ 74,110	$ 61,304	$ 69,026	$ 359,790	$ 278,019	$ 237,162
Operating income (loss)	28,516	(72,058)	27,173	21,185	27,568	32,150	(2,022)	29,539	4,816	87,235	108,720
Net (loss) income attributable to Royal Gold stockholders	$ 20,439	$ (67,656)	$ 15,114	$ (45,046)	$ 14,819	$ 25,014	$ (6,548)	$ 18,680	$ (77,149)	$ 51,965	$ 62,641
Basic (loss) earnings per share (in dollars per share)	$ 0.32	$ (1.04)	$ 0.23	$ (0.69)	$ 0.23	$ 0.38	$ (0.10)	$ 0.29	$ (1.18)	$ 0.80	$ 0.96
Diluted (loss) earnings per share (in dollars per share)	$ 0.32	$ (1.04)	$ 0.23	$ (0.69)	$ 0.23	$ 0.38	$ (0.10)	$ 0.29	$ (1.18)	$ 0.80	$ 0.96