CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 27,484	$ 48,820
Investments - current	120,920	100,918
Accounts and other receivables	1,736	1,235
Prepaid expenses and other current assets	8,925	9,347
Total current assets	159,065	160,320
Property and equipment, net	272	293
Investments - noncurrent	25,604	17,040
Long-term deposits	4,306	4,324
Deferred tax assets	7,217	7,217
Other assets	654	916
Total assets	197,118	190,110
Current liabilities:
Accounts payable	22	86
Accrued compensation	770	2,029
Deferred revenue - current	4,766	4,766
Other current liabilities	14,046	12,465
Total current liabilities	19,604	19,346
Deferred revenue - noncurrent	11,440	12,629
Other long-term liabilities	345	435
Total liabilities	31,389	32,410
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock and additional paid-in capital	322,847	322,714
Accumulated other comprehensive income	577	202
Accumulated deficit	(61,738)	(70,016)
Treasury stock	(95,957)	(95,200)
Total stockholders’ equity	165,729	157,700
Total liabilities and stockholders’ equity	$ 197,118	$ 190,110