Income and Mining Taxes Valuation Allowance (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 375,911	$ 436,829
UNITED STATES
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	292,446	292,677
ARGENTINA
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	6,197	8,376
CANADA
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	1,296	1,718
BOLIVIA
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	37,372	45,177
Mexico
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	13,033	63,373
NEW ZEALAND
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	23,717	25,508
Other Countries
Income Tax Examination [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 1,850	$ 0