Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 126,823	$ 10,186
Marketable securities	86,607	82,627
Interest receivable	383	338
Accounts receivable	5,360	3,155
Prepaid expenses	370	457
Restricted cash	320	320
Other current assets	349	191
Total current assets	220,212	97,274
Marketable securities, non-current	30,384	38,663
Property and equipment, net	1,410	1,406
Intangible assets, in-process research and development	1,870	1,870
Goodwill	1,585	1,585
Other assets	39	40
Total assets	255,500	140,838
Current liabilities:
Accounts payable and accrued liabilities	6,112	4,380
Accrued compensation and employee benefits	1,471	3,194
Escrow liability	275	275
Deferred revenues	8,548	2,282
Total current liabilities	16,406	10,131
Deferred revenues, non-current	19,301	6,679
Contingent consideration liability	1,620	1,570
Deferred tax liability	748	748
Total liabilities	38,075	19,128
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value; 80,000,000 shares authorized, 67,822,302 and 62,243,892 shares issued and outstanding at March 31, 2014 and December 31, 2013, respectively	678	622
Additional paid-in capital	526,431	423,209
Accumulated deficit	(309,705)	(302,133)
Accumulated other comprehensive income	21	12
Total stockholders' equity	217,425	121,710
Total liabilities and stockholders' equity	$ 255,500	$ 140,838