CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Warrants	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit	Total
Balance at Dec. 31, 2015	$ 1,359,144		$ (825)	$ (940,027)	$ 418,292
Balance (in shares) at Dec. 31, 2015	298,634,000
Increase (Decrease) in Shareholders' Equity
Stock-based compensation (note 9)	$ 770				770
Return of capital distribution (note 8)	(2,986)				(2,986)
Exercise of stock options (note 8)	$ 3,500				$ 3,500
Exercise of stock options (note 8) (in shares)	1,377,000				1,377,085
Share repurchase	$ (582)				$ (582)
Share repurchase (in shares)	(558,000)
Unrealized gain on available-for-sale securities, net of taxes (note 2)			2,672		2,672
Other comprehensive income (note 2)					1,800
Net income				25,546	25,546
Balance at Sep. 30, 2016	$ 1,359,846		1,847	(914,481)	447,212
Balance (in shares) at Sep. 30, 2016	299,453,000
Balance at Dec. 31, 2016	$ 1,360,345		1,666	(918,972)	443,039
Balance (in shares) at Dec. 31, 2016	299,570,000
Increase (Decrease) in Shareholders' Equity
Stock-based compensation (note 9)	$ 1,082				1,082
Return of capital distribution (note 8)	(3,059)				(3,059)
Shares issued in connection with the acquisition of Lexam VG Gold (note 15)	$ 38,141				38,141
Shares issued in connection with the acquisition of Lexam VG Gold (note 15) (in shares)	12,687,000
Exercise of stock options (note 8)	$ 47				47
Exercise of stock options (note 8) (in shares)	20,000
Shares issued in connection with the equity issuance (note 8)	$ 39,397				39,397
Shares issued in connection with the equity issuance (note 8) (in shares)	20,700,000
Other comprehensive income (note 2)			1,582		1,582
Net income				(12,800)	(12,800)
Balance at Sep. 30, 2017	$ 1,435,953	$ 3,822	$ 3,248	$ (931,772)	511,251
Balance (in shares) at Sep. 30, 2017	332,977,000
Increase (Decrease) in Shareholders' Equity
Warrants issued in connection with the equity issuance (note 8)		$ 3,822			$ 3,822