Segment Reporting (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financial information relating to reporting segments
Revenue		$ 163,267	$ 185,554
Revenues		163,267	185,554
Costs applicable to sales	[1]	99,340	114,490
Amortization		30,777	38,693
Exploration		6,683	5,252
Other operating expenses		13,029	13,962
Fair value adjustments, net, pretax		4,987	(1,200)
Interest expense, net		(5,965)	(3,579)
Other, net		180	20,799
Income and mining tax benefit (expense)		(11,949)	(10,878)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		691	18,299
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		550	364
Assets, Net	[2]	1,424,210	1,023,211	$ 1,344,553
Capital expenditures		42,345	23,591
Palmarejo [Member]
Financial information relating to reporting segments
Revenue		70,037	77,704
Costs applicable to sales	[1]	31,096	43,001
Amortization		16,325	20,150
Exploration		3,970	1,631
Other operating expenses		731	301
Fair value adjustments, net, pretax		0	0
Interest expense, net		(119)	(125)
Other, net		(2,144)	1,794
Income and mining tax benefit (expense)		(12,443)	(12,245)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		3,209	2,045
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		0	0
Assets, Net	[2]	377,146	401,623
Capital expenditures		9,293	6,230
Rochester [Member]
Financial information relating to reporting segments
Revenue		33,497	38,979
Costs applicable to sales	[1]	24,305	26,439
Amortization		4,831	5,816
Exploration		33	144
Other operating expenses		884	810
Fair value adjustments, net, pretax		0	(1,200)
Interest expense, net		(98)	(117)
Other, net		(40)	(32)
Income and mining tax benefit (expense)		(371)	(498)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		2,935	3,923
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		0	0
Assets, Net	[2]	245,881	227,526
Capital expenditures		2,633	10,568
Silvertip [Member]
Financial information relating to reporting segments
Revenue		0
Costs applicable to sales	[1]	0
Amortization		0
Exploration		0
Other operating expenses		20
Fair value adjustments, net, pretax		0
Interest expense, net		(410)
Other, net		362
Income and mining tax benefit (expense)		835
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		767
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		0
Assets, Net	[2]	361,212
Capital expenditures		18,629
Kensington [Member]
Financial information relating to reporting segments
Revenue		36,300	37,964
Costs applicable to sales	[1]	28,630	28,443
Amortization		6,717	9,178
Exploration		1,590	839
Other operating expenses		321	345
Fair value adjustments, net, pretax		0	0
Interest expense, net		(243)	(40)
Other, net		(37)	(808)
Income and mining tax benefit (expense)		0	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		(1,238)	(1,689)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		0	0
Assets, Net	[2]	215,244	204,987
Capital expenditures		11,364	5,521
Wharf [Member]
Financial information relating to reporting segments
Revenue		23,433	30,251
Costs applicable to sales	[1]	15,309	16,320
Amortization		2,657	3,111
Exploration		10	0
Other operating expenses		665	619
Fair value adjustments, net, pretax		0	0
Interest expense, net		(12)	(19)
Other, net		(21)	89
Income and mining tax benefit (expense)		(639)	(957)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		4,120	9,314
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		0	0
Assets, Net	[2]	104,805	104,673
Capital expenditures		344	887
Other Mining Properties [Member]
Financial information relating to reporting segments
Revenue		0	656
Costs applicable to sales	[1]	0	287
Amortization		247	438
Exploration		1,080	2,638
Other operating expenses		10,408	11,887
Fair value adjustments, net, pretax		4,987	0
Interest expense, net		(5,083)	(3,278)
Other, net		2,060	19,756
Income and mining tax benefit (expense)		669	2,822
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent		(9,102)	4,706
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		550	364
Assets, Net	[2]	119,922	84,402
Capital expenditures		$ 82	$ 385

[1] Excludes amortization.

[2] Segment assets include receivables, prepaids, inventories, property, plant and equipment, and mineral interest