Note 15 - Leases - Lease Cost (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Operating lease cost		$ 25.1	[1]	$ 27.5	[1]	$ 23.3
Finance lease cost(b)	[2]	0.2		0.3		0.4
Total lease cost		$ 25.3		$ 27.8		$ 23.7
Operating leases, weighed-average remaining lease term (Year)		3 years 4 months 24 days		3 years 8 months 12 days
Finance leases, weighed-average remaining lease term (Year)		1 year		1 year 6 months
Operating leases, weighed-average discount rate		3.80%		3.70%
Finance leases, weighed-average discount rate		2.50%		2.50%
Operating cash flows from operating leases		$ 19.7		$ 22.7
Financing cash flows from finance leases		0.1		0.3
Lease assets obtained in exchange for new finance lease liabilities		0.0		0.1
Lease assets obtained in exchange for new operating lease liabilities		$ 14.8		$ 26.4

[1] Includes short-term lease costs of $3.5 million and $3.1 million and variable lease costs of $1.6 million and $2.4 million for the years ended December 31, 2020 and December 31, 2019, respectively.

[2] Includes amortization of leased assets and interest on lease liabilities.