Income and Mining Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income tax provision from continuing operations
Income (loss) before income and mining taxes	$ (22,479)	$ (13,117)	$ (72,636)	$ (95,496)
Income and mining tax benefit (expense)	8,260	16,583	8,451	18,650
United States - Alternative minimum tax [Member]
Income Tax Examination [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	(16,168)	(14,954)	(46,640)	(75,168)
Income tax provision from continuing operations
Federal tax expense (benefit)	(1,080)	739	1,123	447
Argentina [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(731)	(935)	(2,083)	(3,828)
Foreign tax expense (benefit)	(2)	1,539	(3)	5,622
Mexico [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(1,412)	(283)	(16,666)	(28,999)
Foreign tax expense (benefit)	11,951	17,003	11,234	20,831
BOLIVIA
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(4,483)	3,199	(8,081)	11,848
Foreign tax expense (benefit)	(1,029)	(2,969)	(2,240)	(7,937)
Other Countries [Member]
Income tax provision from continuing operations
Income (Loss) from Continuing Operations before Income Taxes, Foreign	315	(144)	834	651
Foreign tax expense (benefit)	$ (1,580)	$ 271	$ (1,663)	$ (313)