CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares
REVENUE:
Revenue	$ 128,822	$ 67,724	$ 60,388
COSTS AND EXPENSES:
Gross profit	35,493	22,544	32,255
OTHER OPERATING EXPENSES:
Property holding	3,896	3,879	3,536
General and administrative	23,163	18,872	12,734
Loss (income) from investment in Minera Santa Cruz S.A. (note 7)	11,865	44	(12,951)
Depreciation	1,178	1,453	1,169
Revision of estimates and accretion of asset reclamation obligations (note 8)	3,464	2,061	595
Impairment of property and equipment (note 6)		711
Total other operating expenses	82,035	48,571	16,908
Operating (loss) income	(46,542)	(26,027)	15,347
OTHER (EXPENSE) INCOME:
Interest and other (expense) income	(1,619)	(938)	835
(Loss) gain on sale of assets	(77)	11	24
(Loss) gain on investments (note 3)	(3,324)	257	519
Foreign currency gain	3,922	694	581
Total other (expense) income	(1,098)	24	1,959
(Loss) income before income and mining taxes	(47,640)	(26,003)	17,306
Income and mining tax recovery (note 9)	2,770	15,369	3,749
Net (loss) income	(44,870)	(10,634)	21,055
OTHER COMPREHENSIVE (LOSS) INCOME:
Reclassification of unrealized gain on marketable equity securities disposed of during the period, net of taxes (note 3)		(840)
Other-than-temporary impairment on marketable equity securities (note 3)		(356)	(882)
Unrealized gain on marketable equity securities, net of taxes		1,818	1,609
Comprehensive (loss) income	$ (44,870)	$ (9,300)	$ 23,546
Net (loss) income per share (note 12):
Basic and Diluted (in dollars per share) | $ / shares	$ (0.13)	$ (0.03)	$ 0.07
Weighted average common shares outstanding (thousands) (note 12):
Basic (in shares) | shares	337,297,000	313,887,000	298,772,000
Diluted (in shares) | shares	337,297,000	313,887,000	300,474,000
Shareholders' distribution declared per common share (note 10) | $ / shares	0.010	0.010	0.005
Gold and silver sales
REVENUE:
Revenue	$ 128,175	$ 67,465	$ 60,388
Other revenue
REVENUE:
Revenue	647	259
Production costs applicable to sales
COSTS AND EXPENSES:
Cost of goods and services sold	93,329	45,180	28,133
Mine development
COSTS AND EXPENSES:
Cost of goods and services sold	3,667	3,837	3,866
Exploration
COSTS AND EXPENSES:
Cost of goods and services sold	$ 34,802	$ 17,714	$ 7,959