Note 16 - Income Taxes - Components of Income Before Taxes and Provision for (Benefit from) Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Domestic	$ 48,446	$ 50,181	$ 48,608
Foreign	(2,244)	689	(354)
Income before income taxes	46,202	50,870	48,254
Current provision:
Federal	12,608	14,982	14,572
State	2,737	3,265	3,635
Foreign	31	302	249
	15,376	18,549	18,456
Deferred provision:
Federal	(426)	(70)	(370)
State	(68)	(84)	(33)
Foreign	(496)	(72)	(557)
	(990)	(226)	(960)
Total provision	$ 14,386	$ 18,323	$ 17,496