EARNINGS PER SHARE ("EPS") (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
EARNINGS PER SHARE ("EPS")
Net income available to Royal Gold common stockholders (in dollars)	$ 6,464	$ 25,999	$ 58,450	$ 71,904
Weighted-average shares for basic EPS	64,837,598	58,953,216	62,723,061	56,486,455
Effect of other dilutive securities (in shares)	156,919	216,098	194,393	252,350
Weighted-average shares for diluted EPS	64,994,517	59,169,314	62,917,454	56,738,805
Basic earnings per share (in dollars per share)	$ 0.10	$ 0.44	$ 0.93	$ 1.27
Diluted earnings per share (in dollars per share)	$ 0.10	$ 0.44	$ 0.93	$ 1.26
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)	$ 105.31		$ 105.31