CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 48,820	$ 51,490
Investments-current	100,918	86,431
Accounts and other receivables	1,235	1,970
Prepaid expenses and other current assets	9,347	13,432
Total current assets	160,320	153,323
Property and equipment, net	293	444
Investments-noncurrent	17,040	7,286
Long-term deposits	4,324	9,658
Deferred tax assets	7,217	2,115
Other assets	916	2,694
Total assets	190,110	175,520
Current liabilities:
Accounts payable	86	2
Accrued compensation	2,029	555
Deferred revenue-current	4,766	4,826
Other current liabilities	12,465	11,247
Total current liabilities	19,346	16,630
Deferred revenue - noncurrent	12,629	16,699
Other long-term liabilities	435	896
Total liabilities	32,410	34,225
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock and additional paid-in capital – $0.001 par value; 100,000,000 shares authorized; 46,974,629 and 46,534,198 shares issued, respectively; 32,247,047 and 34,390,765 shares outstanding, respectively	322,714	323,296
Accumulated other comprehensive income	202	412
Accumulated deficit	(70,016)	(100,680)
Treasury stock at cost: 14,727,582 and 12,143,433 shares, respectively	(95,200)	(81,733)
Total stockholders’ equity	157,700	141,295
Total liabilities and stockholders’ equity	$ 190,110	$ 175,520