QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
QUARTERLY RESULTS OF OPERATIONS (UNAUDITED)
Royalty revenues	$ 57,326	$ 74,166	$ 79,870	$ 77,862	$ 60,109	$ 69,638	$ 68,842	$ 64,465	$ 289,224	$ 263,054	$ 216,469
Operating income	29,926	42,933	50,833	47,812	37,107	42,893	39,420	37,468	171,504	156,888	118,925
Net income attributable to Royal Gold Stockholders	$ 10,703	$ 6,464	$ 27,216	$ 24,770	$ 20,571	$ 25,999	$ 23,411	$ 22,495	$ 69,153	$ 92,476	$ 71,395
Basic earnings per share (in dollars per share)	$ 0.16	$ 0.10	$ 0.42	$ 0.42	$ 0.35	$ 0.44	$ 0.42	$ 0.41	$ 1.09	$ 1.61	$ 1.29
Diluted earnings per share (in dollars per share)	$ 0.16	$ 0.10	$ 0.42	$ 0.41	$ 0.34	$ 0.44	$ 0.42	$ 0.40	$ 1.09	$ 1.61	$ 1.29