CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 25,820	$ 48,820
Investments - current	131,718	100,918
Accounts and other receivables	2,343	1,235
Prepaid expenses and other current assets	8,135	9,347
Total current assets	168,016	160,320
Property and equipment, net	252	293
Investments - noncurrent	20,249	17,040
Long-term deposits	6,304	4,324
Deferred tax assets	7,217	7,217
Other assets	455	916
Total assets	202,493	190,110
Current liabilities:
Accounts payable	54	86
Accrued compensation	1,306	2,029
Deferred revenue - current	4,766	4,766
Other current liabilities	15,734	12,465
Total current liabilities	21,860	19,346
Deferred revenue - noncurrent	10,250	12,629
Other long-term liabilities	347	435
Total liabilities	32,457	32,410
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock and additional paid-in capital	322,870	322,714
Accumulated other comprehensive income	875	202
Accumulated deficit	(54,710)	(70,016)
Treasury stock	(98,999)	(95,200)
Total stockholders’ equity	170,036	157,700
Total liabilities and stockholders’ equity	$ 202,493	$ 190,110