Note 4 - Management Actions (Details Textual) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Charges, Total		$ 4.1	$ 6.2
Notes Receivable, Write-down		0.0	0.0	$ 2.7
Selling, General and Administrative Expenses [Member]
Notes Receivable, Write-down	$ 2.7
Cost of Sales [Member]
Inventory Write-down			1.7	$ 3.3
Employee Severance [Member]
Restructuring Charges, Total		4.1	8.6
Employee Severance [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Charges, Total		3.3	7.1
Employee Severance [Member] | Cost of Sales [Member]
Restructuring Charges, Total		$ 0.8	1.5
Other Restructuring [Member]
Restructuring Charges, Total			$ 2.4