Note 3 - Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Sales	$ 1,001.0	$ 1,137.6	$ 1,123.5
Sales Channel, Directly to Consumer [Member]
Net Sales	664.9	750.9	735.2
Sales Channel, Through Intermediary [Member]
Net Sales	336.1	386.7	388.3
Equipment Sales [Member]
Net Sales	629.7	741.8	730.0
Parts and Consumables [Member]
Net Sales	205.8	221.9	222.3
Specialty Service Coatings [Member]
Net Sales	22.7	25.7	29.8
Service and Other [Member]
Net Sales	142.8	148.2	141.4
Americas [Member]
Net Sales	631.0	722.4	691.0
EMEA [Member]
Net Sales	278.2	307.6	335.6
Asia Pacific [Member]
Net Sales	$ 91.8	$ 107.6	$ 96.9