CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
REVENUE:
Revenue	$ 117,019	$ 128,175	$ 67,465
OPERATING EXPENSES:
Depreciation and depletion	(24,753)	(15,079)	(4,036)
Gross profit	8,986	32,082	20,080
OTHER OPERATING EXPENSES:
Advanced projects	(9,520)	(15,063)	(11,129)
Exploration	(37,744)	(36,576)	(18,624)
General and administrative	(12,785)	(11,125)	(12,344)
Loss from investment in Minera Santa Cruz S.A. (note 9)	(8,754)	(11,865)	(44)
Depreciation	(566)	(1,178)	(1,453)
Revision of estimates and accretion of asset retirement obligations (note 12)	(3,531)	(3,464)	(2,061)
Impairment of property and equipment (note 8)			(711)
Total other operating expenses	(72,900)	(79,271)	(46,366)
Operating loss	(63,914)	(47,189)	(26,286)
OTHER (EXPENSE) INCOME:
Interest and other finance expense, net	(6,817)	(1,619)	(938)
Other income (note 4)	7,140	1,168	1,221
Total other income (expense)	323	(451)	283
Loss before income and mining taxes	(63,591)	(47,640)	(26,003)
Income and mining tax recovery (note 19)	3,844	2,770	15,369
Net loss	(59,747)	(44,870)	(10,634)
OTHER COMPREHENSIVE (LOSS) INCOME:
Reclassification of unrealized gain on marketable equity securities disposed of during the period, net of taxes			(840)
Other-than-temporary impairment on marketable equity securities			356
Unrealized gain on marketable equity securities, net of taxes			1,818
Comprehensive (loss)	$ (59,747)	$ (44,870)	$ (9,300)
Net loss per share (note 14):
Basic and Diluted (in dollars per share)	$ (0.17)	$ (0.13)	$ (0.03)
Weighted average common shares outstanding (thousands) (note 14):
Basic and Diluted (in shares)	361,845	337,297	313,887
Shareholders' distribution declared per common share (note 13)		0.010	0.010
Gold and silver sales
REVENUE:
Revenue	$ 117,019	$ 128,175	$ 67,465
Production costs applicable to sales
OPERATING EXPENSES:
Cost of goods and services sold	$ (83,280)	$ (81,014)	$ (43,349)