Condensed Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	140,000	70,000
Common stock, shares issued	27,641	27,637
Common stock, shares outstanding	27,641	27,637
Series D Redeemable Convertible Preferred Stock
Series D Redeemable convertible preferred stock, par value	$ 0.01	$ 0.01
Series D Redeemable convertible preferred stock, shares authorized	1,124	1,124
Series D Redeemable convertible preferred stock, shares issued	1,124	1,124
Series D Redeemable convertible preferred stock, shares outstanding	1,124	1,124
Series D Redeemable convertible preferred stock, redemption amount	$ 9,149
Series D Redeemable convertible preferred stock, liquidation preference	$ 9,309
Series A Preferred Stock
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	5,000	5,000
Preferred Stock, shares issued	1	1
Preferred Stock, shares outstanding	1	1
Series A Preferred Stock, shares designated	1,500	1,500