Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 100,259	$ 96,089
Accounts receivable, net of allowance for doubtful accounts of $339 in 2019 and $332 in 2018	34,556	51,570
Prepaid expenses and other current assets	8,026	9,562
Total current assets	142,841	157,221
Property and equipment, net	38,969	35,681
Operating lease right-of-use assets, net	7,581
Goodwill	2,293	1,923
Intangible assets, net	6,538	5,064
Deferred tax assets	23,100	19,044
Other non-current assets	8,025	6,972
Total assets	229,347	225,905
Current liabilities:
Accounts payable	2,203	2,454
Accrued compensation and related benefits	4,313	4,727
Accrued and other current liabilities	2,452	3,235
Operating lease liabilities – current portion	1,826
Deferred revenues – current portion	8,612	8,477
Billings in excess of recognized revenues	1,219	635
Total current liabilities	20,625	19,528
Long-term income taxes payable	3,565	3,751
Non-current operating lease liabilities	7,726
Other non-current liabilities	2,444	2,831
Total liabilities	34,360	26,110
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.00015 par value, 5,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $0.00015 par value, 70,000 shares authorized: shares issued 41,596 and 40,677, respectively; shares outstanding 32,350 and 32,382, respectively	5	5
Additional paid-in-capital	322,183	310,660
Treasury stock at cost, 9,246 and 8,295 shares, respectively	(90,908)	(79,142)
Accumulated deficit	(34,540)	(30,452)
Accumulated other comprehensive loss	(1,753)	(1,276)
Total stockholders’ equity	194,987	199,795
Total liabilities and stockholders’ equity	$ 229,347	$ 225,905