Financing (Details 9) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Statement [Line Items]
Beginning balance, December 31, 2012:	$ 70,126
Fair value adjustments:
Compound embedded derivatives	(21,469)	(13,035)
Warrant derivatives	3,003	11,347
Hybrid instruments	(197,392)	11,926
Conversions:
August 24, 2006 financing	(644)
December 29, 2006 financing	(503)
March 27, 2007 financing	(242)
April 11, 2008 financing	(71)
July 29, 2008 financing	(234)
October 18, 2008 financing	(23)
July 15, 2009 financing	(823)
August 14, 2009 financing	(475)
February 8, 2011 financing	(28)
April 13, 2011 financing	(199)
October 25, 2011 financing	(37)
December 8, 2011 financing	(217)
February 6, 2012 financing	(29)
March 26, 2012 financing	(141)
June 1, 2012 financing	(567)
Ending balance, December 31, 2013	281,741	70,126
Series C Preferred Stock [Member]
Fair value adjustments:
Compound embedded derivatives	(20,036)	(2,066)
Conversions:
Series C Preferred Stock	(10)
Series D Preferred Stock [Member]
Fair value adjustments:
Compound embedded derivatives	(1,448)	(1,286)
Warrant derivatives	588	1,826
Embedded Derivative Financial Instruments [Member]
Statement [Line Items]
Beginning balance, December 31, 2012:	2,147
Fair value adjustments:
Compound embedded derivatives	21,469
Warrant derivatives	0
Hybrid instruments	0
Conversions:
August 24, 2006 financing	0
December 29, 2006 financing	0
March 27, 2007 financing	0
April 11, 2008 financing	0
July 29, 2008 financing	0
October 18, 2008 financing	0
July 15, 2009 financing	0
August 14, 2009 financing	0
February 8, 2011 financing	0
April 13, 2011 financing	0
October 25, 2011 financing	0
December 8, 2011 financing	0
February 6, 2012 financing	0
March 26, 2012 financing	0
June 1, 2012 financing	0
Ending balance, December 31, 2013	23,606
Embedded Derivative Financial Instruments [Member] | Series C Preferred Stock [Member]
Conversions:
Series C Preferred Stock	(10)
Warrant [Member]
Statement [Line Items]
Beginning balance, December 31, 2012:	3,687
Fair value adjustments:
Compound embedded derivatives	0
Warrant derivatives	(3,003)
Hybrid instruments	0
Conversions:
August 24, 2006 financing	0
December 29, 2006 financing	0
March 27, 2007 financing	0
April 11, 2008 financing	0
July 29, 2008 financing	0
October 18, 2008 financing	0
July 15, 2009 financing	0
August 14, 2009 financing	0
February 8, 2011 financing	0
April 13, 2011 financing	0
October 25, 2011 financing	0
December 8, 2011 financing	0
February 6, 2012 financing	0
March 26, 2012 financing	0
June 1, 2012 financing	0
Ending balance, December 31, 2013	684
Warrant [Member] | Series C Preferred Stock [Member]
Conversions:
Series C Preferred Stock	0
Hybrid Instrument [Member]
Statement [Line Items]
Beginning balance, December 31, 2012:	64,292
Fair value adjustments:
Compound embedded derivatives	0
Warrant derivatives	0
Hybrid instruments	197,392
Conversions:
August 24, 2006 financing	(644)
December 29, 2006 financing	(503)
March 27, 2007 financing	(242)
April 11, 2008 financing	(71)
July 29, 2008 financing	(234)
October 18, 2008 financing	(23)
July 15, 2009 financing	(823)
August 14, 2009 financing	(475)
February 8, 2011 financing	(28)
April 13, 2011 financing	(199)
October 25, 2011 financing	(37)
December 8, 2011 financing	(217)
February 6, 2012 financing	(29)
March 26, 2012 financing	(141)
June 1, 2012 financing	(567)
Ending balance, December 31, 2013	257,451
Hybrid Instrument [Member] | Series C Preferred Stock [Member]
Conversions:
Series C Preferred Stock	$ 0