BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 9,023	$ 17,399
Short-term investments available-for-sale	35,256	26,712
Restricted cash	217	986
Accounts receivables	2,602	1,011
Unbilled receivables	1,571	1,570
Prepaid expenses	2,167	2,559
Other current assets	886	171
Total current assets	51,722	50,408
Investments available-for-sale	1,117	6,233
Property and equipment, net	11,617	11,456
Goodwill	33,141	33,141
Restricted cash	757	756
Other non-current assets	350	351
Total assets	98,704	102,345
Current liabilities:
Accounts payable	2,173	3,228
Accrued expenses and other current liabilities	5,842	7,275
Deferred revenue	78	258
Current portion of capital lease	59	58
Current portion of notes payable	390	157
Warrant liability	267	267
Deferred rent	444	432
Total current liabilities	9,253	11,675
Deferred revenue	2,500	2,500
Non-current portion of capital lease	222	237
Non-current portion of notes payable	1,290	753
Deferred rent	7,871	6,940
Total liabilities	21,136	22,105
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 2,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.01 par value, 200,000,000 shares authorized; and 151,700,247 shares issued and 151,244,817 shares outstanding at March 31, 2013 and 148,398,747 shares issued and 147,943,317 shares outstanding at December 31, 2012	1,517	1,484
Additional paid-in capital	446,191	438,939
Accumulated deficit	(368,159)	(358,163)
Treasury stock, 455,430 shares, cost basis	(2,450)	(2,450)
Accumulated other comprehensive income	469	430
Total stockholders' equity	77,568	80,240
Total liabilities and stockholders' equity	$ 98,704	$ 102,345