Quarterly report pursuant to Section 13 or 15(d)

Stock Plans (Details)

Stock Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Summary of share-based compensation expense recorded for awards under the stock option plans
Total share-based compensation expenses	$ 505	$ 1,552
Research and development [Member]
Summary of share-based compensation expense recorded for awards under the stock option plans
Total share-based compensation expenses	304	616
General and administrative [Member]
Summary of share-based compensation expense recorded for awards under the stock option plans
Total share-based compensation expenses	$ 201	$ 936

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References + Details