Equity Incentive Plans (Details 1) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock option activity
Number of Shares Outstanding, Beginning Balance	7,205	7,856	10,169
Number of Shares Granted, Shares	2,592	260	200
Number of Shares Exercised, Shares	(50)	(25)	(138)
Number of Shares Forfeited or cancelled, Shares	(1,540)	(886)	(2,375)
Number of Shares Outstanding, Ending Balance	8,207	7,205	7,856
Number of Share Exercisable, Ending Balance	6,266
Number of Shares Expected to vest, Ending Balance	1,941
Weighted-Average Exercise Price, Beginning Balance	$ 6.68	$ 7.12	$ 8.90
Weighted-Average Exercise Price, Granted	$ 1.64	$ 2.03	$ 2.87
Weighted-Average Exercise Price, Exercised	$ 0.46	$ 1.73	$ 1.73
Weighted-Average Exercise Price, Forfeited or Cancelled	$ 9.72	$ 9.39	$ 14.68
Weighted-Average Exercise Price, Ending Balance	$ 4.55	$ 6.68	$ 7.12
Weighted-Average Exercise Price Exercisable, Ending Balance	$ 5.46
Weighted-Average Exercise Price Expected to Vest, Ending Balance	$ 1.64
Weighted-Average Remaining Contractual Life (Years), Ending Balance	5 years 4 months 21 days
Weighted-Average Remaining Contractual Life (Years) Exercisable	4 years 2 months 9 days
Weighted-Average Remaining Contractual Life (Years) Expected to Vest	9 years 3 months 1 day
Aggregate Intrinsic Value Exercised	$ 45	$ 14	$ 192
Aggregate Intrinsic Value, Ending Balance	244
Aggregate Intrinsic Value, Exercisable	180
Aggregate Intrinsic Value Expected to Vest, Ending Balance	$ 64