CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit	Total
Balance at Dec. 31, 2013	$ 1,354,696	$ (295)	$ (607,634)	$ 746,767
Balance (in shares) at Dec. 31, 2013	297,159
Increase (Decrease) in Shareholders' Equity
Stock-based compensation (note 12)	$ 1,324			1,324
Exercise of stock options (note 11)	$ 1,932			1,932
Exercise of stock options (note 11 ) (in shares)	1,499
Exercise of stock options assumed from Minera Andes Inc. acquisition	$ 360			360
Exercise of stock options assumed from Minera Andes Inc. acquisition (in shares)	198
Shares issued for the settlement of accounts payable	$ 1,004			1,004
Shares issued for settlement of accounts payable (in shares)	394
Shares issued to terminate back-in right	$ 1,352			1,352
Shares issued to terminate back-in right (in shares)	850
Unrealized gain (loss) on available-for-sale securities, net of taxes (note 3)		419		419
Net income (loss)			(311,943)	(311,943)
Balance at Dec. 31, 2014	$ 1,360,668	124	(919,577)	441,215
Balance (in shares) at Dec. 31, 2014	300,100
Increase (Decrease) in Shareholders' Equity
Stock-based compensation (note 12)	$ 1,305			1,305
Return of capital distribution (note 11)	$ (1,503)			(1,503)
Exercise of stock options (note 11 ) (in shares)	0
Shares issued for the settlement of accounts payable	$ 443			443
Shares issued for settlement of accounts payable (in shares)	430
Unrealized gain (loss) on available-for-sale securities, net of taxes (note 3)		(949)		(949)
Share repurchase (note 11)	$ (1,769)			$ (1,769)
Share repurchase (note 11) (in shares)	(1,896)			(1,896,442)
Net income (loss)			(20,450)	$ (20,450)
Balance at Dec. 31, 2015	$ 1,359,144	(825)	(940,027)	418,292
Balance (in shares) at Dec. 31, 2015	298,634
Increase (Decrease) in Shareholders' Equity
Stock-based compensation (note 12)	$ 1,039			1,039
Return of capital distribution (note 11)	(2,986)			(2,986)
Exercise of stock options (note 11)	$ 3,730			$ 3,730
Exercise of stock options (note 11 ) (in shares)	1,494			1,457,000
Unrealized gain (loss) on available-for-sale securities, net of taxes (note 3)		1,609		$ 1,609
Share repurchase (note 11)	$ (582)			(582)
Share repurchase (note 11) (in shares)	(558)
Other-than-temporary impairment on marketable equity securities (note 3)		882		882
Net income (loss)			21,055	21,055
Balance at Dec. 31, 2016	$ 1,360,345	$ 1,666	$ (918,972)	$ 443,039
Balance (in shares) at Dec. 31, 2016	299,570