Stockholders' Equity - Common and Preferred Shares (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Summary of the Company's stock option activity under its 2005 Plan
Shares, Options outstanding at December 31, 2011	1,002
Shares, Granted	1,488
Shares, Forfeited and expired	(691)
Shares, Options outstanding at September 30, 2012	1,799	1,002
Shares, Options exercisable at September 30, 2012	616
Shares, Options vested or expected to vest at September 30, 2012	1,259
Weighted Average Exercise Price, Options outstanding at December 31, 2011	$ 5.91
Weighted Average Exercise Price, Granted	$ 0.82
Weighted Average Exercise Price, Forfeited and expired	$ 6.01
Weighted Average Exercise Price, Options outstanding at September 30, 2012	$ 1.66	$ 5.91
Weighted Average Exercise Price, Options exercisable at September 30, 2012	$ 1.23
Weighted Average Exercise Price, Options vested or expected to vest at September 30, 2012	$ 1.28
Weighted Average Remaining Contractual Life, Options outstanding at December 31, 2011	8 years 11 months 1 day	9 years 2 months 19 days
Weighted Average Remaining Contractual Life, Options outstanding at September 30, 2012	8 years 11 months 1 day	9 years 2 months 19 days
Weighted Average Remaining Contractual Life, Options exercisable at September 30, 2012	9 years 6 months 26 days
Weighted Average Remaining Contractual Life, Options vested or expected to vest at September 30, 2012	9 years 6 months 22 days