Financing (Details 6) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	$ (197,392)	$ 13,088
Less: Day-one loss from debenture financings	0	(1,162)
Gain (loss) from change in fair value of hybrid financial instruments	(197,392)	11,926
Debentures 2006 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	100	2,680
Debentures 2007 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	13,343	798
Debentures 2008 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	2,339	5,433
Debentures 2009 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	1,249	708
Debentures 2010 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	7,178	1,858
Debentures 2011 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	(3,146)	840
Debentures 2012 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	(7,060)	771
Debentures 2013 Series [Member]
Debt Conversion [Line Items]
Unrealized Gain Loss On Hybrid Instrument Gross	$ (211,395)	$ 0