Mining Properties (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Mining Properties
Operational mining properties:	$ 629,002	$ 557,799
Accumulated depletion	(410,112)	(368,410)
Operational mining properties, net	218,890	189,389
Mineral interest	1,029,743	679,429
Accumulated depletion	(397,043)	(367,626)
Mineral interest, net	632,700	311,803
Total mining properties	851,590	501,192
Palmarejo [Member]
Mining Properties
Operational mining properties:	159,604	137,821
Accumulated depletion	(129,872)	(121,906)
Operational mining properties, net	29,732	15,915
Mineral interest	822,036	521,349
Accumulated depletion	(345,199)	(332,032)
Mineral interest, net	476,837	189,317
Total mining properties	506,569	205,232
San Bartolome [Member]
Mining Properties
Operational mining properties:	49,491	49,305
Accumulated depletion	(29,389)	(26,106)
Operational mining properties, net	20,102	23,199
Mineral interest	17,560	17,560
Accumulated depletion	(11,157)	(10,143)
Mineral interest, net	6,403	7,417
Total mining properties	26,505	30,616
Kensington [Member]
Mining Properties
Operational mining properties:	231,230	217,138
Accumulated depletion	(124,090)	(106,865)
Operational mining properties, net	107,140	110,273
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	107,140	110,273
Rochester [Member]
Mining Properties
Operational mining properties:	156,097	153,535
Accumulated depletion	(123,085)	(113,533)
Operational mining properties, net	33,012	40,002
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	33,012	40,002
Wharf [Member]
Mining Properties
Operational mining properties:	32,580
Accumulated depletion	(3,676)
Operational mining properties, net	28,904
Mineral interest	49,601
Accumulated depletion	(8,240)
Mineral interest, net	41,361
Total mining properties	70,265
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
Operational mining properties, net	$ 0	0
Mineral interest	81,461	81,461
Accumulated depletion	(32,447)	(25,451)
Mineral interest, net	49,014	56,010
Total mining properties	$ 49,014	$ 56,010