CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 59,522	$ 86,478
Short-term investments	0	3,019
Accounts and other receivables	2,218	3,385
Prepaid expenses and other current assets	12,610	14,078
Total current assets	74,350	106,960
Property and equipment, net	209	1,226
Long-term deposits	12,571	7,062
Other assets, net	9,000	9,600
Total assets	96,130	124,848
Current liabilities:
Accounts payable	149	809
Accrued compensation	1,001	2,844
Other current liabilities	2,457	3,478
Deferred revenue	5,173	4,692
Total current liabilities	8,780	11,823
Long-term deferred revenue	21,334	25,952
Other long-term liabilities	2,035	3,316
Total liabilities	32,149	41,091
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock and additional paid-in capital – $0.001 par value; 100,000,000 shares authorized; 39,161,214 and 38,624,784 shares issued, respectively; 27,017,781 and 31,414,328 shares outstanding, respectively	258,756	253,289
Accumulated other comprehensive income	122	124
Accumulated deficit	(113,164)	(118,565)
Treasury stock at cost: 12,143,433 and 7,210,456 shares, respectively	(81,733)	(51,091)
Total stockholders’ equity	63,981	83,757
Total liabilities and stockholders’ equity	$ 96,130	$ 124,848