Mining Properties (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Mining Properties
Operational mining properties:	$ 598,579	$ 557,799
Accumulated depletion	(382,467)	(368,410)
Operational mining properties, net	216,112	189,389
Mineral interest	731,234	679,429
Accumulated depletion	(374,504)	(367,626)
Mineral interest, net	356,730	311,803
Total mining properties	572,842	501,192
Palmarejo [Member]
Mining Properties
Operational mining properties:	143,012	137,821
Accumulated depletion	(124,306)	(121,906)
Operational mining properties, net	18,706	15,915
Mineral interest	521,349	521,349
Accumulated depletion	(335,791)	(332,032)
Mineral interest, net	185,558	189,317
Total mining properties	204,264	205,232
San Bartolome [Member]
Mining Properties
Operational mining properties:	49,379	49,305
Accumulated depletion	(27,411)	(26,106)
Operational mining properties, net	21,968	23,199
Mineral interest	17,560	17,560
Accumulated depletion	(10,435)	(10,143)
Mineral interest, net	7,125	7,417
Total mining properties	29,093	30,616
Kensington [Member]
Mining Properties
Operational mining properties:	220,957	217,138
Accumulated depletion	(113,005)	(106,865)
Operational mining properties, net	107,952	110,273
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	107,952	110,273
Rochester [Member]
Mining Properties
Operational mining properties:	153,613	153,535
Accumulated depletion	(117,414)	(113,533)
Operational mining properties, net	36,199	40,002
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	36,199	40,002
Wharf [Member]
Mining Properties
Operational mining properties:	31,618
Accumulated depletion	(331)
Operational mining properties, net	31,287
Mineral interest	51,779
Accumulated depletion	(676)
Mineral interest, net	51,103
Total mining properties	82,390
Endeavor [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	49,085	49,059
Accumulated depletion	0	0
Mineral interest, net	49,085	49,059
Total mining properties	49,085	49,059
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	10,000
Accumulated depletion	0	0
Mineral interest, net	10,000	10,000
Total mining properties	10,000	10,000
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	81,461
Accumulated depletion	(27,602)	(25,451)
Mineral interest, net	53,859	56,010
Total mining properties	$ 53,859	$ 56,010