Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 18,476	$ 16,766
Marketable securities	41,167	67,366
Interest receivable	199	331
Accounts receivable	3,241	919
Prepaid expenses	579	310
Total current assets	63,662	85,692
Marketable securities, non-current	21,077
Property and equipment, net	1,532	1,603
Other assets	41	41
Total assets	86,312	87,336
Current liabilities:
Accounts payable and accrued liabilities	2,649	5,515
Accrued compensation and employee benefits	1,295	1,672
Deferred revenues	2,208	17
Total current liabilities	6,152	7,204
Deferred revenues, non-current portion	9,931
Total liabilities	16,083	7,204
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value; 80,000,000 shares authorized, 52,722,314 and 52,554,795 shares issued and outstanding at June 30, 2012 and December 31, 2011, respectively	527	526
Additional paid-in capital	335,950	332,839
Accumulated deficit	(266,241)	(253,245)
Accumulated other comprehensive income (loss)	(7)	12
Total stockholders' equity	70,229	80,132
Total liabilities and stockholders' equity	$ 86,312	$ 87,336