Note 11 - Geographic Information and Major Customer and Product Data - Revenues Within Geographical Areas (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Total revenues		$ 217,364	$ 164,456	$ 127,210
UNITED STATES
Total revenues		134,438	100,281	73,343
EMEA [Member]
Total revenues	[1]	70,128	52,410	44,994
Rest of World [Member]
Total revenues		$ 12,798	$ 11,765	$ 8,873

[1] Sales to customers in France accounted for $22,762, $17,129 and $13,570 for the years ended December 31, 2017, 2016 and 2015, respectively.