Financing (Details 8) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Unrealized Gain Loss On Hybrid Instrument Gross	$ 13,088	$ 5,351
Less: Day-one loss from debenture financings	(1,162)	0
Gain (loss) from change in fair value of derivative liability	11,926	5,351
Debentures 2006 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	2,680	0
Debentures 2007 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	798	4,003
Debentures 2008 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	5,433	1,348
Debentures 2009 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	708	0
Debentures 2010 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	1,858	0
Debentures 2011 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	840	0
Debentures 2012 Series [Member]
Unrealized Gain Loss On Hybrid Instrument Gross	$ 771	$ 0