Fair Value of Financial Instruments (Schedule of Level 3 liabilities included in Non-current Liabilities on the Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Warrant Liability
Initial value of interest make-whole payment	$ (8,619)	$ (144)	$ (8,540)	$ (472)
Convertible notes, net of discount	59,100		59,100
Fair Value
Warrant Liability
Convertible notes, net of discount	115,000		115,000
Warrants To Purchase Common Stock [Member]
Warrant Liability
Balance at the beginning of the period			251
Initial value of interest make-whole payment			9,270
Changes in fair value of derivative liabilities included in earnings			8,540
Balance at the end of the period	$ 18,061		$ 18,061