Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income (loss)	$ (217,805)	$ (7,640)	$ (224,065)	$ (17,771)	$ (92,025)	$ (62,671)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization and depreciation	2,529	1,997	5,097	3,843
Accretion of asset retirement obligation			78	35
Foreign currency loss on loss contingency			(260)	(118)
Foreign currency (gain) loss on deferred tax liability			423	(189)
Impairment of goodwill	11,180		11,180
Impairment (reversal of impairment) of accounts receivable				35
Impairment of long lived assets	238,020		238,020
Asset write off			60	425
Write off of loss contingency			(299)
Realized loss on marketable securities			133
Fair value of stock/warrants received for mineral rights				(101)
Gain on sale of assets, net			(3,236)	(1,860)
Income tax provision			(47,495)	(2,960)
Stock compensation			979	523
Changes in operating assets and liabilities:
Increase (decrease) in trade accounts receivable			(21)	(1,812)
Decrease in prepaid expenses and other assets			241	278
Decrease (increase) in inventories			1,564	(149)
Decrease (increase) in value added tax recoverable, net			1,674	(1,409)
Decrease in reclamation liability			(6)
Increase (decrease) in accounts payable and accrued liabilities			(767)	(1,641)
Decrease in deferred leasehold payments			(88)	(48)
Net cash used in operating activities			$ (16,788)	$ (22,919)