Acquisitions (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	1 Months Ended
	Apr. 16, 2013 Orko Silver Corporation [Member]	Dec. 31, 2013 Global Royalty Corp [Member]
Business Combination, Consideration Transferred [Abstract]
Common shares issued	$ 173,363	$ 22,198
Cash	99,059	3,849
Warrants (1,588,768 valued at $3.64 per warrant)	5,777
Transaction advisory fees and other acquisition costs	17,642	300
Total purchase price	295,841	26,047
Current liabilities	2,616	679
Deferred income taxes	114,339	7,926
Total liabilities assumed	116,955	8,605
Total Consideration	412,796	34,652
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Cash	3,487	165
Other current assets	635	276
Metal and other inventory		111
Mineral interests	408,352	34,100
Other assets	322
Total assets acquired	$ 412,796	$ 34,652
Common shares issued for acquisition	11,572,918	2,130,351,000
Common shares issued, price per share	$ 14.98	$ 10,420
Number of warrants issued	1,588,768,000
Warrants, price per warrant	$ 3,640