Financing (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	$ (1,369)	$ 4,495	$ (2,542)	$ 28,549
Debentures 2006 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	(83)	1,048	(144)	6,657
Debentures 2007 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	(35)	1,083	(49)	6,878
Debentures 2008 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	(82)	1,309	(140)	8,315
Debentures 2009 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	(1)	253	(6)	1,605
Debentures 2010 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	0	0	0	0
Debentures 2011 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	(35)	496	(61)	3,150
Debentures 2012 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	(41)	117	(86)	742
Debentures 2013 Series [Member]
Debt Conversion [Line Items]
Gain (loss) from changes in fair value of hybrid instruments	$ (1,092)	$ 189	$ (2,056)	$ 1,202