STOCKHOLDERS' EQUITY (Details) (USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2012	Jun. 30, 2012 item	Jun. 30, 2011	Jun. 30, 2010
Preferred Stock
Number of authorized and unissued shares (in shares)		10,000,000	10,000,000
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common Stock Offering
Shares sold	4,000,000
Sale price per share (in dollars per share)	$ 67.1
Proceeds from shares sold	$ 268,400,000	$ 271,536,000		$ 276,839,000
Number of stock options exercised (in shares)		184,357	20,738
Proceeds from stock options exercised		$ 4,100,000	$ 400,000
Exchange ratio for conversion of exchangeable shares of RG Exchangeco into shares of Royal Gold common stock		1
Stockholders' Rights Plan
Number of preferred stock purchase rights for each share of Company common stock held		1
Minimum percentage of company's outstanding shares of common stock accumulated by acquiring party for rights to become exercisable		15.00%
Fraction of newly issued share of Series A junior participating preferred stock that could be purchased, for each Right		0.001
Value of a share of the Company's common stock allowed to be purchased for each Right, as a multiple of the exercise price of the Right		2
Initial exercise price of the Right (in dollars per right)		$ 175