EARNINGS PER SHARE ("EPS") (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
EARNINGS PER SHARE ("EPS")
Net income available to Royal Gold common stockholders (in dollars)	$ 16,636	$ 20,143	$ 10,667	$ 15,195	$ 10,701	$ 6,464	$ 27,217	$ 24,771	$ 62,641	$ 69,153	$ 92,476
Weighted-average shares for basic EPS									64,909,149	63,250,247	57,220,040
Effect of other dilutive securities (in shares)									117,107	179,575	243,810
Weighted-average shares for diluted EPS									65,026,256	63,429,822	57,463,850
Basic earnings per share (in dollars per share)	$ 0.26	$ 0.31	$ 0.16	$ 0.23	$ 0.16	$ 0.10	$ 0.42	$ 0.42	$ 0.96	$ 1.09	$ 1.61
Diluted earnings per share (in dollars per share)	$ 0.26	$ 0.31	$ 0.16	$ 0.23	$ 0.16	$ 0.10	$ 0.42	$ 0.41	$ 0.96	$ 1.09	$ 1.61
Exchange ratio for conversion of exchangeable shares of RG Exchangeco into shares of Royal Gold common stock									1
Impact on diluted earnings per share (in dollars per share)									$ 0
2019 Conversion Notes, Initial conversion price per share of common stock (in dollars per share)	$ 105								$ 105