Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 7,877	$ 12,590
Marketable securities	83,228	83,840
Accounts receivable	150,354	44
Prepaid expenses and other current assets	2,192	1,201
Total current assets	243,651	97,675
Property and equipment, net	2,508	2,310
Patents, licenses, and other intangible assets, net	10,353	9,971
Marketable securities - long term	77,666	96,891
Other assets	103	63
Total assets	334,281	206,910
Current liabilities
Accounts payable	7,694	6,400
Accrued expenses	3,278	3,634
Current portion of deferred rent	137	108
Current portion of deferred revenue	103,063	33,287
Income taxes	1,781
Total current liabilities	115,953	43,429
Deferred rent, less current portion	424	507
Deferred revenue, less current portion	9,307	542
Total liabilities	125,684	44,478
Commitments and contingencies
Stockholders' equity
Common stock, $0.01 par value: 200,000,000 authorized shares at June 30, 2016 and December 31, 2015; 40,944,080 issued and outstanding at June 30, 2016 and 40,551,039 issued and outstanding at December 31, 2015	409	405
Additional paid-in capital	428,790	424,128
Accumulated other comprehensive income (loss)	216	(516)
Accumulated deficit	(220,818)	(261,585)
Total stockholders' equity	208,597	162,432
Total liabilities and stockholders' equity	$ 334,281	$ 206,910