Note 15 - Segment Reporting - Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 46,117	$ 40,573	$ 129,917	$ 117,251
Products Excluding Consumables and Skincare [Member]
Revenue	34,958	33,197	99,706	95,727
Hand Piece Refills [Member]
Revenue	2,510	1,055	7,109	2,881
Skincare [Member]
Revenue	2,847	1,423	6,230	3,981
Product [Member]
Revenue	40,315	35,675	113,045	102,589
Service [Member]
Revenue	5,802	4,898	16,872	14,662
UNITED STATES
Revenue	26,425	24,329	74,972	73,597
JAPAN
Revenue	7,511	5,021	18,142	12,522
Asia, Excluding Japan [Member]
Revenue	3,754	4,348	11,396	11,422
Europe [Member]
Revenue	1,907	2,356	7,147	6,729
Rest of World [Member]
Revenue	$ 6,520	$ 4,519	$ 18,260	$ 12,981