CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash	$ 62,958	$ 51,490
Marketable Securities, Current	83,532	86,431
Accounts and other receivables	2,079	1,970
Prepaid expenses and other current assets	11,788	13,432
Total current assets	160,357	153,323
Property and equipment, net	405	444
Long-term deposits	4,917	9,658
Debt Securities, Available-for-sale, Noncurrent	11,181	7,286
Other assets, net	4,001	4,809
Total assets	180,861	175,520
Current liabilities:
Accounts payable	53	2
Accrued compensation	567	555
Contract with Customer, Liability, Current	4,736	4,826
Other current liabilities	15,955	11,247
Total current liabilities	21,311	16,630
Long-term deferred revenue	15,494	16,699
Other long-term liabilities	706	896
Total liabilities	37,511	34,225
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock and additional paid-in capital	324,476	323,296
Accumulated other comprehensive income	653	412
Accumulated deficit	(95,604)	(100,680)
Treasury stock	(86,175)	(81,733)
Total stockholders’ equity	143,350	141,295
Total liabilities and stockholders’ equity	$ 180,861	$ 175,520