INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE - Summary of Operating Results from MSC (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE
Revenue from gold and silver sales	$ 18,291	$ 36,383	$ 49,691	$ 51,966
Production costs applicable to sales	(22,354)	(24,699)	(50,741)	(35,848)
Depreciation and depletion	(4,812)	(7,007)	(11,510)	(10,013)
Gross Profit	(8,875)	4,677	(12,560)	6,105
Net income (loss) before tax	(19,844)	(13,515)	(120,129)	(23,533)
Net loss	(19,814)	(13,014)	(119,005)	(23,150)
Income tax recovery	30	501	1,124	383
(Loss) from investment in MSC, net of amortization	$ (1,045)	(4,137)	$ (3,721)	(6,447)
Subsidiary (as a percent)			100.00%
Ownership interest (as a percent)	49.00%		49.00%
Shutdown Costs	$ 1,968		$ 1,968
Cost of Sales And Other Expenses
INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE
Shutdown Costs	5,900		7,200
MSC
INVESTMENT IN MINERA SANTA CRUZ S.A. ("MSC") - SAN JOSE MINE
Revenue from gold and silver sales	47,081	65,997	84,471	114,818
Production costs applicable to sales	(30,402)	(46,514)	(58,718)	(76,047)
Depreciation and depletion	(7,650)	(16,545)	(14,977)	(31,925)
Gross Profit	9,029	2,938	10,776	6,846
Exploration	(2,175)	(2,553)	(5,041)	(5,891)
Other expenses	(8,925)	(979)	(11,142)	(3,532)
Net income (loss) before tax	(2,071)	(594)	(5,407)	(2,577)
Current and deferred tax expense	1,884	(3,049)	1,933	(3,838)
Net loss	(187)	(3,643)	(3,474)	(6,415)
Net income (loss)	(92)	(1,785)	(1,703)	(3,143)	$ (2,097)
Amortization of fair value increments	(1,251)	(2,459)	(2,636)	(4,372)	(9,448)
Income tax recovery	298	107	618	1,068	$ 2,791
(Loss) from investment in MSC, net of amortization	$ (1,045)	$ (4,137)	$ (3,721)	$ (6,447)
Ownership interest (as a percent)	49.00%		49.00%