Income Taxes Schedule of Components of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Assets, Gross [Abstract]
Offering costs	$ 120	$ 595
Non-capital loss carryovers	222,213	191,182
Capital loss carryovers	741	907
Mine property costs	7,118	7,154
Reclamation costs	9,765	6,638
Unrealized loss	508	(173)
Other	9,609	5,061
Valuation allowance	(163,890)	(131,208)
Future tax assets	86,184	80,156
Deferred tax liabilities [Abstract]
Mine property costs	114,595	102,948
Deferred Tax Liabilities, Derivatives	4	1,094
Other	0	107
Deferred tax liabilities	114,599	104,149
Net deferred tax assets/(liabilities)	$ 28,415	$ 23,993