Mining Properties (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Mining Properties
Operational mining properties:	$ 833,841	$ 804,845
Accumulated depletion	(496,358)	(485,368)
Operational mining properties, net	337,483	319,477
Mineral interest	976,443	969,341
Accumulated depletion	(470,105)	(459,249)
Mineral interest, net	506,338	510,092
Total mining properties	843,821	829,569
Palmarejo [Member]
Mining Properties
Operational mining properties:	220,141	214,383
Accumulated depletion	(151,102)	(146,598)
Operational mining properties, net	69,039	67,785
Mineral interest	629,303	629,303
Accumulated depletion	(445,327)	(435,215)
Mineral interest, net	183,976	194,088
Total mining properties	253,015	261,873
Rochester [Member]
Mining Properties
Operational mining properties:	194,390	193,881
Accumulated depletion	(146,245)	(144,390)
Operational mining properties, net	48,145	49,491
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	48,145	49,491
Silvertip [Member]
Mining Properties
Operational mining properties:	70,626	57,214
Accumulated depletion	0	0
Operational mining properties, net	70,626	57,214
Mineral interest	245,116	245,116
Accumulated depletion	0	0
Mineral interest, net	245,116	245,116
Total mining properties	315,742	302,330
Kensington [Member]
Mining Properties
Operational mining properties:	307,996	298,749
Accumulated depletion	(182,555)	(178,632)
Operational mining properties, net	125,441	120,117
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	125,441	120,117
Wharf [Member]
Mining Properties
Operational mining properties:	40,688	40,618
Accumulated depletion	(16,456)	(15,748)
Operational mining properties, net	24,232	24,870
Mineral interest	45,837	45,837
Accumulated depletion	(24,655)	(24,034)
Mineral interest, net	21,182	21,803
Total mining properties	45,414	46,673
La Preciosa [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	49,085	49,085
Accumulated depletion	0	0
Mineral interest, net	49,085	49,085
Total mining properties	49,085	$ 49,085
Other Mining Properties [Member]
Mining Properties
Operational mining properties:	0
Accumulated depletion	0
Operational mining properties, net	0
Mineral interest	7,102
Accumulated depletion	(123)
Mineral interest, net	6,979
Total mining properties	$ 6,979