Income and Mining Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	$ (40,500)	$ (11,367)	$ (82,380)	$ 12,148
Income tax provision from continuing operations	(2,621)	(23,673)	2,068	(34,918)
United States - Alternative minimum tax [Member]
Income Tax Examination [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	(31,370)	(67,824)	(60,214)	(61,896)
Income tax provision from continuing operations
Federal tax expense (benefit)	(146)	(1,329)	(292)	(4,541)
Argentina [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(688)	(2,989)	(2,892)	(6,981)
Foreign tax expense (benefit)	(349)	(117)	4,083	(44)
Mexico [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(12,710)	47,214	(28,716)	58,756
Foreign tax expense (benefit)	107	(15,798)	3,828	(19,471)
Bolivia [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	3,957	12,122	8,649	21,628
Foreign tax expense (benefit)	(2,205)	(4,556)	(4,969)	(8,884)
Other Countries [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	311	110	793	641
Foreign tax expense (benefit)	$ (28)	$ (1,873)	$ (582)	$ (1,978)