Note 8 - Intangible Assets (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Trade Names, Gross	$ 23.3	$ 23.3
Customer Relationships [Member]
Finite-Lived Intangible Assets, Gross, Total	21.7	21.7
Finite-lived Intangible Assets Acquired		2.5
Amortization of Intangible Assets, Total	1.8	1.6	$ 1.3
Finite-Lived Intangible Assets, Accumulated Amortization	$ 16.1	$ 14.3
Finite-lived Intangible Assets, Remaining Weighted Average Useful Life	4 years	4 years 292 days