Financing (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	$ 218,656	$ 6,774
Debentures 2006 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	11,471	1,887
Debentures 2007 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	2,637	2,329
Debentures 2008 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	10,927	1,657
Debentures 2009 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	863	(74)
Debentures 2010 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	0	623
Debentures 2011 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	4,879	249
Debentures 2012 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	8,356	103
Debentures 2013 Series [Member]
Debt Conversion [Line Items]
Gain from changes in fair value of hybrid instruments	$ 179,523	$ 0