Note 10 - Segment Information and Revenue by Geography and Products - Revenue by Geographic Region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer, Including Assessed Tax	$ 181,712	$ 162,720	$ 151,493
Systems [Member]
Revenue from Contract with Customer, Including Assessed Tax	140,478	132,594	125,883
Hand Piece Refills [Member]
Revenue from Contract with Customer, Including Assessed Tax	9,648	4,162	2,435
Skincare [Member]
Revenue from Contract with Customer, Including Assessed Tax	8,512	5,778	4,342
Product [Member]
Revenue from Contract with Customer, Including Assessed Tax	158,638	142,535	132,660
Service [Member]
Revenue from Contract with Customer, Including Assessed Tax	23,074	20,185	18,833
UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	106,243	101,862	94,581
JAPAN
Revenue from Contract with Customer, Including Assessed Tax	24,142	17,819	17,264
Asia, Excluding Japan [Member]
Revenue from Contract with Customer, Including Assessed Tax	16,110	15,467	13,719
Europe [Member]
Revenue from Contract with Customer, Including Assessed Tax	10,596	8,875	8,317
Rest of World [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 24,620	$ 18,696	$ 17,612