Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 21,679	$ 16,766
Marketable securities	41,868	67,366
Interest receivable	190	331
Accounts receivable	4,129	919
Other current assets	203
Prepaid expenses	296	310
Total current assets	68,365	85,692
Marketable securities, non-current	12,584
Property and equipment, net	1,543	1,603
Other assets	41	41
Total assets	82,533	87,336
Current liabilities:
Accounts payable and accrued liabilities	4,013	5,515
Accrued compensation and employee benefits	2,473	1,672
Deferred revenues	2,304	17
Total current liabilities	8,790	7,204
Deferred revenue, non-current	8,847
Total liabilities	17,637	7,204
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value; 80,000,000 shares authorized, 53,058,525 and 52,554,795 shares issued and outstanding at December 31, 2012 and 2011, respectively	531	526
Additional paid-in capital	339,848	332,839
Accumulated deficit	(275,509)	(253,245)
Accumulated other comprehensive income	26	12
Total stockholders' equity	64,896	80,132
Total liabilities and stockholders' equity	$ 82,533	$ 87,336