Condensed Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 81,013	$ 45,791
Marketable securities	183,295	94,407
Accounts receivable	28,770	391
Prepaid expenses and other current assets	9,294	4,864
Total current assets	302,372	145,453
Marketable securities	32,476
Property and equipment, net	5,008	4,532
Other assets	230	456
Restricted cash	705	607
Total assets	340,791	151,048
Current liabilities:
Accounts payable	12,938	9,247
Accrued expenses	10,277	10,121
Loans payable, net of discount	6,039	5,766
Deferred revenue	2,230	16,693
Other liabilities	1,249
Deferred rent	268	266
Total current liabilities	33,001	42,093
Loans payable, net of current portion and discount	17,815	17,636
Deferred revenue, net of current portion	20,331	16,509
Deferred rent, net of current portion	446	553
Other liabilities	1,238	2,487
Stockholders' equity:
Preferred stock, $.001 par value: 5,000 shares authorized at June 30, 2011 and December 31, 2010, respectively; no shares issued and outstanding at June 30, 2011 and December 31, 2010, respectively
Common stock, $.001 par value: 100,000 shares authorized at June 30, 2011 and December 31, 2010, respectively; 42,901 and 35,604 shares issued and outstanding at June 30, 2011 and December 31, 2010, respectively	43	36
Additional paid-in capital	424,732	308,268
Accumulated other comprehensive income (loss)	64	(20)
Accumulated deficit	(156,879)	(236,514)
Total stockholders' equity	267,960	71,770
Total liabilities and stockholders' equity	$ 340,791	$ 151,048