Condensed Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Per Share data	Jun. 30, 2011	Dec. 31, 2010
Stockholders' equity:
Preferred stock, par or stated value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000	5,000
Common stock, par or stated value	$ 0.001	$ 0.001
Common stock, shares authorized	70,000	70,000
Common stock, shares issued	27,626	27,596
Common stock, shares outstanding	27,626	27,596
Series A convertible preferred stock
Stockholders' equity:
Preferred stock, designated shares	1,500	1,500
Preferred stock, shares issued	1	1
Preferred stock, shares outstanding	1	1