CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 110,988	$ 24,622
Short-term investments	13,930	21,916
Accounts and other receivables	1,051	806
Prepaid expenses and other current assets	9,856	736
Total current assets	135,825	48,080
Property and equipment, net	2,343	3,150
Deferred income tax assets	295	401
Other assets, net	7,532	344
Total assets	145,995	51,975
Current liabilities:
Accounts payable	3,612	6,647
Accrued compensation	3,948	4,133
Other current liabilities	3,194	3,896
Deferred revenue	4,591	4,424
Total current liabilities	15,345	19,100
Long-term deferred revenue	30,203	22,303
Other long-term liabilities	787	915
Total liabilities	46,335	42,318
Commitments and contingencies (Notes 14 and 15)
Stockholders’ equity:
Common stock and additional paid-in capital – $0.001 par value; 100,000,000 shares authorized; 37,652,498 and 35,950,518 shares issued, respectively; 30,829,351 and 29,263,828 shares outstanding, respectively	246,415	228,046
Accumulated other comprehensive income	116	99
Accumulated deficit	(98,521)	(171,616)
Treasury stock at cost: 6,823,147 and 6,686,690 shares, respectively	(48,350)	(46,872)
Total stockholders’ equity	99,660	9,657
Total liabilities and stockholders’ equity	$ 145,995	$ 51,975