Organization and Summary of Significant Accounting Policies (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
Fair value of the warrant liability
Total warrant liability at December 31, 2012			$ 8,240
Fair value of warrants transferred to equity upon exercise			(4,686)
Adjustment to record warrants at fair value upon exercise and at June 30,2013	(5,362)	(1,955)	(2,317)	(1,939)
Total warrant liability at June 30, 2013	$ 1,237		$ 1,237