Mining Properties (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Mining Properties
Operational mining properties:	$ 557,799	$ 641,305
Accumulated depletion	(368,410)	(315,541)
Operational mining properties, net	189,389	325,764
Mineral interest	679,429	1,753,129
Accumulated depletion	(367,626)	(327,392)
Mineral interest, net	311,803	1,425,737
Total mining properties	501,192	1,751,501
Palmarejo [Member]
Mining Properties
Operational mining properties:	137,821	151,845
Accumulated depletion	(121,906)	(110,143)
Operational mining properties, net	15,915	41,702
Mineral interest	521,349	1,146,572
Accumulated depletion	(332,032)	(300,187)
Mineral interest, net	189,317	846,385
Total mining properties	205,232	888,087
San Bartolome [Member]
Mining Properties
Operational mining properties:	49,305	70,761
Accumulated depletion	(26,106)	(22,236)
Operational mining properties, net	23,199	48,525
Mineral interest	17,560	26,643
Accumulated depletion	(10,143)	(8,759)
Mineral interest, net	7,417	17,884
Total mining properties	30,616	66,409
Kensington [Member]
Mining Properties
Operational mining properties:	217,138	268,351
Accumulated depletion	(106,865)	(80,032)
Operational mining properties, net	110,273	188,319
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	110,273	188,319
Rochester [Member]
Mining Properties
Operational mining properties:	153,535	150,348
Accumulated depletion	(113,533)	(103,130)
Operational mining properties, net	40,002	47,218
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	40,002	47,218
Endeavor [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	49,059	408,352
Accumulated depletion	0	0
Mineral interest, net	49,059	408,352
Total mining properties	49,059	408,352
Joaquin Project - Argentina [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	10,000	93,429
Accumulated depletion	0	0
Mineral interest, net	10,000	93,429
Total mining properties	10,000	93,429
Other Mining Properties [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	81,461	78,133
Accumulated depletion	(25,451)	(18,446)
Mineral interest, net	56,010	59,687
Total mining properties	$ 56,010	$ 59,687