Income and Mining Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax benefit (expense) from continuing operations	$ 565,295	$ 283,038	$ (41,819)
State tax provision from continuing operations	20,253	2,245	(3,151)
Percentage depletion and related deductions	0	0	7,461
Change in valuation allowance	(128,344)	(106,802)	(12,651)
Non-deductible imputed interest	0	(214)	(525)
Uncertain tax positions	(4,425)	(5,209)	(9,849)
U.S. and foreign non-deductible expenses	(4,892)	(2,383)	(4,206)
Foreign exchange rates	23,672	13,937	(10,416)
Foreign inflation and indexing	3,765	2,937	712
Foreign tax rate differences	(63,930)	(24,108)	3,967
Foreign withholding and other foreign taxes	91,882	(100,331)	(5,861)
Foreign tax credits and other, net	(44,032)	13,153	5,531
Change in Mexico permanent reinvestment assertion	0	81,853	0
Income and mining tax (expense) benefit	$ 459,244	$ 158,116	$ (70,807)