Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 49,410	$ 143,480
Marketable debt securities	435,623	153,767
Marketable equity securities	26,885	36,860
Accounts receivable	54,284	66,384
Prepaid expenses	19,734	23,877
Total current assets	585,936	424,368
Property and equipment, net	38,855	28,240
Patents, licenses, and other intangible assets, net	17,944	16,493
Marketable debt securities - long term	140,413	300,465
Marketable equity securities - long term	31,124	31,262
Notes receivable - long term	5,000	5,000
Right of use (ROU) asset	31,440	31,730
Other assets	613	653
Total assets	851,325	838,211
Current liabilities
Accounts payable	15,747	14,001
Accrued expenses	16,348	19,443
Lease liabilities	7,647
Deferred revenue	35,299	37,294
Total current liabilities	75,041	70,738
Lease liabilities, net of current portion	33,943	33,969
Total liabilities	108,984	104,707
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.01 par value: 10,000,000 authorized shares; -0- issued and outstanding shares at June 30, 2022 and December 31, 2021
Common stock, $0.01 par value: 200,000,000 authorized shares at June 30, 2022 and December 31, 2021; 59,684,420 issued and outstanding at June 30, 2022 and 59,355,558 issued and outstanding at December 31, 2021	598	595
Additional paid-in capital	1,044,172	1,017,523
Accumulated other comprehensive loss	(8,944)	(1,510)
Accumulated deficit	(293,485)	(283,104)
Total stockholders' equity	742,341	733,504
Total liabilities and stockholders' equity	$ 851,325	$ 838,211