CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 215,050	$ 32,335
Marketable securities	112,685	135,721
Restricted cash	0	297
Accounts receivable - billed	6,674	7,510
Account receivable - unbilled	4,196	3,100
Prepaid expenses and other current assets	11,489	9,195
Total current assets	350,094	188,158
Property and equipment, net	23,967	19,737
Intangible assets, net	11,198	12,577
Goodwill	52,664	54,612
Other non-current assets	918	918
Total assets	438,841	276,002
Current liabilities:
Accounts payable	9,742	12,908
Accrued expenses	15,590	19,397
Current portion of notes payable	579	603
Deferred rent	1,161	1,138
Other current liabilities	1,704	70
Total current liabilities	28,776	34,116
Deferred revenue	2,500	2,500
Non-current portion of notes payable	252	395
Deferred rent	7,516	7,734
Other non-current liabilities	91	1,639
Total liabilities	39,135	46,384
Commitments and contingences	0	0
Stockholders’ equity:
Preferred stock, $0.01 par value, 2,000,000 shares authorized; no shares issued and outstanding as of March 31, 2015 and December 31, 2014, respectively	0	0
Common stock, $0.01 par value, 300,000,000 shares authorized; 268,381,979 shares issued and 267,926,549 shares outstanding at March 31, 2015 and 239,287,294 shares issued and 238,831,864 shares outstanding at December 31, 2014	2,684	2,393
Additional paid-in capital	926,691	729,373
Accumulated deficit	(517,463)	(493,093)
Treasury stock, 455,430 shares, cost basis at both March 31, 2015 and December 31, 2014	(2,450)	(2,450)
Accumulated other comprehensive loss	(9,756)	(6,605)
Total stockholders’ equity	399,706	229,618
Total liabilities and stockholders’ equity	$ 438,841	$ 276,002