Mining Properties (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Mining Properties
Operational mining properties:	$ 804,845	$ 648,780
Accumulated depletion	(485,368)	(439,682)
Operational mining properties, net	319,477	209,098
Mineral interest	969,341	771,497
Accumulated depletion	(459,249)	(430,305)
Mineral interest, net	510,092	341,192
Total mining properties	829,569	550,290
Palmarejo [Member]
Mining Properties
Operational mining properties:	214,383	174,890
Accumulated depletion	(146,598)	(134,995)
Operational mining properties, net	67,785	39,895
Mineral interest	629,303	629,303
Accumulated depletion	(435,215)	(381,686)
Mineral interest, net	194,088	247,617
Total mining properties	261,873	287,512
Rochester [Member]
Mining Properties
Operational mining properties:	193,881	165,230
Accumulated depletion	(144,390)	(138,244)
Operational mining properties, net	49,491	26,986
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	49,491	26,986
Silvertip [Member]
Mining Properties
Operational mining properties:	57,214
Accumulated depletion	0
Operational mining properties, net	57,214
Mineral interest	245,116
Accumulated depletion	0
Mineral interest, net	245,116
Total mining properties	302,330
Kensington [Member]
Mining Properties
Operational mining properties:	298,749	271,175
Accumulated depletion	(178,632)	(154,744)
Operational mining properties, net	120,117	116,431
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Total mining properties	120,117	116,431
Wharf [Member]
Mining Properties
Operational mining properties:	40,618	37,485
Accumulated depletion	(15,748)	(11,699)
Operational mining properties, net	24,870	25,786
Mineral interest	45,837	45,837
Accumulated depletion	(24,034)	(19,249)
Mineral interest, net	21,803	26,588
Total mining properties	46,673	52,374
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
Joaquin Project - Argentina
Mining Properties
Operational mining properties:		0
Accumulated depletion
Operational mining properties, net		0
Mineral interest		10,000
Accumulated depletion		0
Mineral interest, net		10,000
Total mining properties		10,000
Other Mining Properties [Member]
Mining Properties
Operational mining properties:		0
Accumulated depletion		0
Operational mining properties, net		0
Mineral interest		37,272
Accumulated depletion		(29,370)
Mineral interest, net		7,902
Total mining properties		$ 7,902