Mining Properties (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Mining Properties
Operational mining properties:	$ 691,872	$ 686,052
Accumulated depletion	(272,487)	(258,978)
Operational mining properties, net	419,385	427,074
Mineral interest	1,822,494	1,822,493
Accumulated depletion	(272,069)	(257,758)
Mineral interest, net	1,550,425	1,564,735
Non-producing and developmental properties	142	142
Total mining properties	1,969,952	1,991,951
Palmarejo [Member]
Mining Properties
Operational mining properties:	158,718	155,722
Accumulated depletion	(87,359)	(82,037)
Operational mining properties, net	71,359	73,685
Mineral interest	1,658,389	1,658,389
Accumulated depletion	(248,942)	(235,795)
Mineral interest, net	1,409,447	1,422,594
Non-producing and developmental properties	0	0
Total mining properties	1,480,806	1,496,279
San Bartolome [Member]
Mining Properties
Operational mining properties:	70,351	70,322
Accumulated depletion	(19,349)	(18,439)
Operational mining properties, net	51,002	51,883
Mineral interest	26,642	26,642
Accumulated depletion	(7,678)	(7,338)
Mineral interest, net	18,964	19,304
Non-producing and developmental properties	0	0
Total mining properties	69,966	71,187
Kensington [Member]
Mining Properties
Operational mining properties:	335,424	333,619
Accumulated depletion	(53,519)	(46,649)
Operational mining properties, net	281,905	286,970
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties	0	0
Total mining properties	281,905	286,970
Rochester [Member]
Mining Properties
Operational mining properties:	115,963	114,973
Accumulated depletion	(100,844)	(100,437)
Operational mining properties, net	15,119	14,536
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties	0	0
Total mining properties	15,119	14,536
Martha [Member]
Mining Properties
Operational mining properties:	11,416	11,416
Accumulated depletion	(11,416)	(11,416)
Operational mining properties, net	0	0
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties	0	0
Total mining properties	0	0
Endeavor [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	44,033	44,033
Accumulated depletion	(15,449)	(14,625)
Mineral interest, net	28,584	29,408
Non-producing and developmental properties	0	0
Total mining properties	28,584	29,408
Joaquin [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	93,430	93,429
Accumulated depletion	0	0
Mineral interest, net	93,430	93,429
Non-producing and developmental properties	0	0
Total mining properties	93,430	93,429
Other [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties	142	142
Total mining properties	$ 142	$ 142