OPERATING SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Segment Reporting
Gold and silver sales				$ 60,388	$ 72,956	$ 45,303
Production costs applicable to sales				(28,133)	(34,607)	(40,608)
Mine development costs				(3,866)	(1,169)	(1,829)
Exploration costs				(7,959)	(8,798)	(11,332)
Property holding costs				(3,536)	(4,336)	(6,365)
General and administrative expenses				(12,734)	(12,045)	(12,069)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)				12,951	2,414	(5,284)
Depreciation				1,169	942	979
Reclamation and Remediation				506	429	407
Revision of estimates and accretion of reclamation obligations				(595)	(429)	(407)
Impairment of mineral property interests and property and equipment					(50,600)	(353,736)
Impairment of investment in MSC					(11,777)	(21,162)
Gain on sale of assets				24	13	26
Gain on sale of marketable securities (note 3)				(22)
Other-than-temporary impairment on marketable equity securities				882	0
Foreign currency gain (loss)				581	1,906	(2,419)
Net Income before income taxes				17,306	(45,010)	(419,113)
Registration Taxes						6,788
Revenues				60,388	72,956	45,303
Long-Lived Assets	$ 420,642			419,744	420,642
Investment in MSC	167,107			162,320	167,107
Mexico
Operating Segment Reporting
Gold and silver sales				60,388	72,956	45,303
Production costs applicable to sales				(28,133)	(34,607)	(40,608)
Mine development costs				(1,174)	(761)	(1,829)
Mine construction costs						(1,723)
Exploration costs				(4,100)	(4,526)	(5,468)
Property holding costs				(1,642)	(2,471)	(1,829)
General and administrative expenses				(2,688)	(3,953)	(3,194)
Segment income (loss)				22,651	26,638	(9,348)
Capital Expenditures					2	(3)
MSC
Operating Segment Reporting
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)				12,951	2,414	(5,284)
Segment income (loss)				12,951	2,414	(5,284)
Los Azules
Operating Segment Reporting
Exploration costs				(1,649)	(1,481)	(2,453)
Property holding costs				(405)	(356)	(610)
General and administrative expenses				(646)	(647)	(969)
Segment income (loss)				(2,700)	(2,484)	(4,032)
Nevada
Operating Segment Reporting
Mine development costs				(2,692)	(408)
Exploration costs				(1,973)	(2,517)	(3,060)
Property holding costs				(1,489)	(1,509)	(3,926)
General and administrative expenses				(228)	(203)	(211)
Segment income (loss)				(6,382)	(4,637)	(7,197)
Capital Expenditures				6,165	764	1,842
Total Segment
Operating Segment Reporting
Gold and silver sales				60,388	72,956	45,303
Production costs applicable to sales				(28,133)	(34,607)	(40,608)
Mine development costs				(3,866)	(1,169)	(1,829)
Mine construction costs						(1,723)
Exploration costs				(7,722)	(8,524)	(10,981)
Property holding costs				(3,536)	(4,336)	(6,365)
General and administrative expenses				(3,562)	(4,803)	(4,374)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)				12,951	2,414	(5,284)
Segment income (loss)				26,520	21,931	(25,861)
Net Income before income taxes				17,306	(45,010)	(419,113)
Capital Expenditures						908
Corporate & Other
Operating Segment Reporting
Exploration costs				(237)	(274)	(351)
General and administrative expenses				(9,172)	(7,242)	(7,695)
Depreciation				(1,169)	942	(979)
Revision of estimates and accretion of reclamation obligations				(595)	(429)	(407)
Impairment of mineral property interests and property and equipment					(50,600)	(353,736)
Impairment of investment in MSC					(11,777)	(21,162)
Interest income and other income				835	2,404	(259)
Gain on sale of assets				(24)	13	26
Gain on sale of marketable securities (note 3)				22
Other-than-temporary impairment on marketable equity securities				(882)
Unrealized gain on derivative instrument (note 2)				(1,379)
Foreign currency gain (loss)				581	1,906	(2,419)
Registration Taxes						6,788
Capital Expenditures				6,165	764	2,750
Bank of Nova Scotia | Sales | Customer
Operating Segment Reporting
Gold and silver sales				$ 58,100	$ 67,200	$ 43,200
Gold and silver sales, percentage				96.00%	92.00%	95.00%
MSC
Operating Segment Reporting
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)				$ 12,951	$ 2,414	$ (5,284)
Impairment of investment in MSC					(11,777)	(21,200)
Investment in MSC	167,107	$ 177,018		162,320	167,107	177,018
Los Azules Copper Project
Operating Segment Reporting
Impairment of mineral property interests and property and equipment	(11,400)	$ (107,900)	$ (120,400)
Capital Expenditures				764	62	2
Los Azules Copper Project | Argentina
Operating Segment Reporting
Impairment of mineral property interests and property and equipment					(11,399)	(228,301)
Canada
Operating Segment Reporting
Long-Lived Assets	763			663	763
Mexico
Operating Segment Reporting
Revenues				60,388	72,956	$ 45,303
Long-Lived Assets	24,067			27,582	24,067
United States
Operating Segment Reporting
Long-Lived Assets	36,967			37,620	36,967
Argentina
Operating Segment Reporting
Long-Lived Assets	$ 358,845			$ 353,879	$ 358,845