Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Components of Derivative Instruments
MHR Convertible Note	$ 1,441	$ 7,367
Derivative instruments, net	4,505	10,199
August 2007 Warrants [Member]
Components of Derivative Instruments
Derivative instruments	0	12
August 2009 Warrants [Member]
Components of Derivative Instruments
Derivative instruments	612	540
June 2010 MHR Warrants [Member]
Components of Derivative Instruments
Derivative instruments	126	351
August 2010 Warrants [Member]
Components of Derivative Instruments
Derivative instruments	874	735
August 2010 MHR Waiver Warrants [Member]
Components of Derivative Instruments
Derivative instruments	168	142
July 2011 Warrants [Member]
Components of Derivative Instruments
Derivative instruments	1,134	929
July 2011 MHR Waiver Warrants [Member]
Components of Derivative Instruments
Derivative instruments	$ 150	$ 123