Mining Properties (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Mining Properties
Operational mining properties:	$ 692,472	$ 686,052
Accumulated depletion	(276,615)	(258,978)
Operational mining properties, net	415,857	427,074
Mineral interest	2,233,037	1,822,493
Accumulated depletion	(291,205)	(257,758)
Mineral interest, net	1,941,832	1,564,735
Non-producing and developmental properties	0	142
Total mining properties	2,357,689	1,991,951
Palmarejo [Member]
Mining Properties
Operational mining properties:	162,855	155,722
Accumulated depletion	(94,647)	(82,037)
Operational mining properties, net	68,208	73,685
Mineral interest	1,660,580	1,658,389
Accumulated depletion	(266,499)	(235,795)
Mineral interest, net	1,394,081	1,422,594
Non-producing and developmental properties	0	0
Total mining properties	1,462,289	1,496,279
San Bartolome [Member]
Mining Properties
Operational mining properties:	70,360	70,322
Accumulated depletion	(20,305)	(18,439)
Operational mining properties, net	50,055	51,883
Mineral interest	26,643	26,642
Accumulated depletion	(8,037)	(7,338)
Mineral interest, net	18,606	19,304
Non-producing and developmental properties	0	0
Total mining properties	68,661	71,187
Kensington [Member]
Mining Properties
Operational mining properties:	338,907	333,619
Accumulated depletion	(60,310)	(46,649)
Operational mining properties, net	278,597	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	278,597	286,970
Rochester [Member]
Mining Properties
Operational mining properties:	120,350	114,973
Accumulated depletion	(101,353)	(100,437)
Operational mining properties, net	18,997	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	18,997	14,536
Martha [Member]
Mining Properties
Operational mining properties:	0
Accumulated depletion	0
Operational mining properties, net	0
Mineral interest	44,033
Accumulated depletion	(16,669)
Mineral interest, net	27,364
Non-producing and developmental properties	0
Total mining properties	27,364
Endeavor [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	408,352	44,033
Accumulated depletion	0	(14,625)
Mineral interest, net	408,352	29,408
Non-producing and developmental properties	0	0
Total mining properties	408,352	29,408
Joaquin [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	93,429	93,429
Accumulated depletion	0	0
Mineral interest, net	93,429	93,429
Non-producing and developmental properties	0	0
Total mining properties	93,429	93,429
Other [Member]
Mining Properties
Operational mining properties:		11,416
Accumulated depletion		(11,416)
Operational mining properties, net		0
Mineral interest		0
Accumulated depletion		0
Mineral interest, net		0
Non-producing and developmental properties		142
Total mining properties		$ 142