Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 18,741	$ 20,471
Marketable securities, available-for-sale	19,864	23,499
Restricted cash	3,246	3,182
Receivables and other assets	5,769	4,178
Total current assets	47,620	51,330
Long-term investments	2,077	1,971
Property and equipment, net	2,010	2,639
Intangible assets, net	1,522	1,660
Other assets	191	379
Total assets	53,420	57,979
Current liabilities:
Accounts payable and accrued expenses	3,364	5,201
Deferred revenue	2,110	0
Total current liabilities	5,474	5,201
Long-term liabilities:
Deferred rent	$ 494	$ 856
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized, none issued and outstanding	$ 0	$ 0
Common stock, $0.01 par value, 160,000 shares authorized, 91,513 and 90,334 shares issued and outstanding at September 30, 2015, and December 31, 2014, respectively	915	903
Additional paid-in capital	448,976	446,698
Accumulated deficit	(402,550)	(395,667)
Accumulated other comprehensive income (loss)	111	(12)
Total stockholders' equity	47,452	51,922
Total liabilities and stockholders' equity	$ 53,420	$ 57,979