Segment Reporting (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Long Lived Assets
Entity Wide Disclosure on Geographic Areas Long Lived Assets in Entity's Country of Domicile and Foreign Countries	$ 2,204,178		$ 2,204,178		$ 2,237,774
Revenues
Total Revenue	170,938	200,825	495,133	577,147
United States [Member]
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	392,225		392,225		384,626
Revenues
Total Revenue	78,284	63,186	198,710	207,689
Australia [Member]
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	22,949		22,949		25,668
Revenues
Total Revenue	2,367	4,296	7,227	10,757
Argentina [Member]
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	94,435		94,435		94,705
Bolivia [Member]
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	226,495		226,495		235,085
Revenues
Total Revenue	28,350	28,819	84,983	111,196
Mexico [Member]
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	1,452,739		1,452,739		1,487,228
Revenues
Total Revenue	61,684	104,524	202,851	248,167
Other Foreign Countries [Member]
Long Lived Assets
Long Lived Assets in Entity's Country of Domicile	15,335		15,335		10,462
Revenues
Total Revenue	$ 253	$ 0	$ 1,362	$ (662)