CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 21,254	$ 16,890
Short-term investments	28,138	36,519
Accounts receivable, net	11,755	9,567
Prepaid expenses and other current assets	646	1,211
Total current assets	61,793	64,187
Property and equipment, net	1,259	1,706
Intangible assets, net	250	266
Other assets	981	1,070
Total assets	64,283	67,229
Current liabilities:
Accounts payable	792	1,085
Accrued compensation	2,338	2,974
Other accrued liabilities	1,905	2,496
Short-term deferred revenue	2,170	2,759
Total current liabilities	7,205	9,314
Long-term deferred revenue	31	106
Other long-term liabilities	446	501
Total liabilities	7,682	9,921
Commitments and contingencies (Note 3)
Stockholders' equity:
Common stock; par value $0.0001, 50,000,000 shares authorized; 19,196,412 issued and 18,713,498 outstanding at September 30, 2017; 19,030,024 issued and 18,548,180 outstanding at December 31, 2016	2	2
Additional paid-in capital	267,722	267,400
Treasury stock, at cost (482,914 shares at September 30, 2017 and 481,844 shares at December 31, 2016)	(5,297)	(5,295)
Accumulated other comprehensive loss	(2,136)	(2,329)
Accumulated deficit	(203,690)	(202,470)
Total stockholders' equity	56,601	57,308
Total liabilities and stockholders' equity	$ 64,283	$ 67,229