Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Stock-Based Compensation [Abstract]

Stock-based compensation expenses

The following table shows total stock-based compensation expenses included in the condensed consolidated statement of operations for the three months ended March 31, 2013 and March 31, 2012 (in thousands):

	Three months ended March 31,
	2013		2012
Costs and expenses:
Research and development	$	685	$	775
General and administrative		644		608
Total stock-based compensation expense	$	1,329	$	1,383