Note 11 - Revenue 1 (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Revenue from Contract with Customers, Including Assessed Tax	$ 0.9	$ 0.4	$ 1.1	$ (1.1)
Contract with Customer, Liability, Revenue Recognized	3.9	$ 6.5	11.2	$ 3.3
Revenue, Remaining Performance Obligation, Amount	$ 143.0		$ 143.0