BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 17,399	$ 14,104
Short-term investments available-for-sale	26,712	4,205
Restricted cash	986
Accounts receivables	1,011	1,965
Unbilled receivables	1,570	1,836
Prepaid expenses	2,559	2,441
Other current assets	171	1,558
Total current assets	50,408	26,109
Investments available-for-sale	6,233
Property and equipment, net	11,456	6,857
Goodwill	33,141	33,141
Restricted cash	756
Other non-current assets	351	469
Total assets	102,345	66,576
Current liabilities:
Accounts payable	3,228	2,645
Accrued expenses and other current liabilities	7,275	4,528
Deferred revenue	258
Current portion of capital lease	58
Current portion of notes payable	157	20
Warrant liability	267
Deferred rent	432	386
Total current liabilities	11,675	7,579
Deferred revenue	2,500	2,500
Non-current portion of capital lease	237
Non-current portion of notes payable	753	300
Warrant liability		368
Deferred rent	6,940	1,980
Total liabilities	22,105	12,727
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 148,398,747 shares issued and 147,943,317 shares outstanding at December 31, 2012 and 117,480,867 shares issued and 117,025,437 shares outstanding at December 31, 2011	1,484	1,175
Additional paid-in capital	438,939	383,948
Accumulated deficit	(358,163)	(329,656)
Treasury stock, 455,430 shares, cost basis	(2,450)	(2,450)
Accumulated other comprehensive income	430	832
Total stockholders' equity	80,240	53,849
Total liabilities and stockholders' equity	$ 102,345	$ 66,576