Note 18 - Quarterly Financial Data (Unaudited) (Details Textual) $ in Millions	3 Months Ended
	Jun. 30, 2017 USD ($)
Decrease in Net Sales from Prior Period	$ 0.4
Increase in Gross Margin From Prior Period	16.3
Increase as Result of Pension Decrease [Member]
Increase in Gross Margin From Prior Period	14.2
North America [Member]
Decrease in Net Sales from Prior Period	0.9
International [Member]
Increase in Net Sales from Prior Period	$ 0.5