Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 73,636	$ 56,689
Short-term investments	85,045	79,868
Trade receivables (net of allowance for doubtful accounts of $395 and $433 at June 30, 2018 and December 31, 2017, respectively)	41,393	75,596
Prepaid expenses and other current assets	16,927	14,346
Total current assets	217,001	226,499
Long-term assets:
Other assets	7,724	7,243
Property and equipment, net	12,342	11,896
Total long-term assets	20,066	19,139
Total assets	237,067	245,638
Current liabilities:
Trade payables	1,899	635
Accrued expenses and other short term liabilities	45,493	42,453
Deferred revenues	71,663	73,493
Total current liabilities	119,055	116,581
Long-term liabilities:
Deferred revenues	6,274	6,608
Other liabilities	7,933	7,807
Total long-term liabilities	14,207	14,415
Stockholders’ equity:
Common stock of $0.001 par value - Authorized: 200,000,000 shares at June 30, 2018 and December 31, 2017; Issued and outstanding: 29,218,030 shares at June 30, 2018 and 28,146,162 shares at December 31, 2017	29	28
Accumulated other comprehensive income (loss)	(2,838)	136
Additional paid-in capital	243,733	223,868
Accumulated deficit	(137,119)	(109,390)
Total stockholders’ equity	103,805	114,642
Total liabilities and stockholders’ equity	$ 237,067	$ 245,638