QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended								12 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009
QUARTERLY RESULTS OF OPERATIONS (UNAUDITED)
Royalty revenues	$ 59,269	$ 55,546	$ 56,316	$ 45,338	$ 40,669	$ 35,043	$ 34,740	$ 26,113	$ 216,469	$ 136,565	$ 73,771
Operating income (loss)	34,634	31,877	31,604	20,810	16,311	(1,231)	15,201	10,754	118,925	41,035	27,292
Net income (loss) available to Royal Gold Stockholders	$ 21,687	$ 19,565	$ 18,312	$ 11,831	$ 10,505	$ (5,754)	$ 9,615	$ 7,126	$ 71,395	$ 21,492	$ 38,348
Basic earnings per share (in dollars per share)	$ 0.39	$ 0.36	$ 0.33	$ 0.22	$ 0.21	$ (0.13)	$ 0.24	$ 0.18	$ 1.29	$ 0.49	$ 1.09
Diluted earnings per share (in dollars per share)	$ 0.39	$ 0.35	$ 0.33	$ 0.21	$ 0.21	$ (0.13)	$ 0.23	$ 0.17	$ 1.29	$ 0.49	$ 1.07