Note 3 - Revenue - Contract Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Sales Incentives [Member]
Beginning balance	$ 12.1	$ 13.7
Additions to sales incentive accrual	38.0	18.2
Contract payments	(30.0)	(20.0)
Foreign currency fluctuations	(0.2)	0.2
Ending balance	19.9	12.1
Maintenance [Member]
Foreign currency fluctuations	(0.1)	(0.6)
Beginning balance	9.3	10.7
Increase in deferred revenue representing our obligation to satisfy future performance obligations	34.5	21.0
Decrease in deferred revenue for amounts recognized in net sales for satisfied performance obligations	(32.5)	(21.8)
Ending balance	$ 11.2	$ 9.3