Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 67,868	$ 56,689
Short-term investments	90,214	79,868
Trade receivables (net of allowance for doubtful accounts of $459 and $433 at September 30, 2018 and December 31, 2017, respectively)	52,938	75,596
Prepaid expenses and other current assets	14,665	14,346
Total current assets	225,685	226,499
Long-term assets:
Other assets	7,601	7,243
Property and equipment, net	12,593	11,896
Total long-term assets	20,194	19,139
Total assets	245,879	245,638
Current liabilities:
Trade payables	3,145	635
Accrued expenses and other short term liabilities	46,104	42,453
Deferred revenues	72,544	73,493
Total current liabilities	121,793	116,581
Long-term liabilities:
Deferred revenues	6,374	6,608
Other liabilities	7,651	7,807
Total long-term liabilities	14,025	14,415
Stockholders’ equity:
Common stock of $0.001 par value - Authorized: 200,000,000 shares at September 30, 2018 and December 31, 2017; Issued and outstanding: 29,424,275 shares at September 30, 2018 and 28,146,162 shares at December 31, 2017	29	28
Accumulated other comprehensive income (loss)	(1,742)	136
Additional paid-in capital	256,210	223,868
Accumulated deficit	(144,436)	(109,390)
Total stockholders’ equity	110,061	114,642
Total liabilities and stockholders’ equity	$ 245,879	$ 245,638