Segment Reporting (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Long Lived Assets
Long Lived Assets, Total	$ 3,015,590		$ 3,015,590		$ 2,675,811
Revenues
Sales of metal	200,825	230,593	577,147	689,563
UNITED STATES
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	525,573		525,573		514,687
Revenues
Sales of metal	63,186	72,694	207,689	157,106
AUSTRALIA
Long Lived Assets
Long Lived Assets in Individual Foreign Countries	26,469		26,469		29,408
Revenues
Sales of metal	4,296	4,132	10,757	16,077
ARGENTINA
Long Lived Assets
Long Lived Assets in Individual Foreign Countries	94,844		94,844		95,134
Revenues
Sales of metal	0	4,933	(662)	12,700
BOLIVIA
Long Lived Assets
Long Lived Assets in Individual Foreign Countries	235,059		235,059		240,905
Revenues
Sales of metal	28,819	46,192	111,196	140,951
MEXICO
Long Lived Assets
Long Lived Assets in Individual Foreign Countries	2,133,645		2,133,645		1,795,677
Revenues
Sales of metal	$ 104,524	$ 102,642	$ 248,167	$ 362,729