Note 11 - Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Finite-lived intangible assets, gross	$ 194.6	$ 151.9
Less accumulated amortization	(69.8)	(61.3)
Total identifiable intangible assets, net	124.8	90.6
Customer Relationships [Member]
Finite-lived intangible assets, gross	$ 168.1	129.9
Weighted average amortization period (Year)	10 years 10 months 24 days
Noncompete Agreements [Member]
Finite-lived intangible assets, gross	$ 9.6	7.3
Weighted average amortization period (Year)	6 years 3 months 18 days
Trade Names [Member]
Finite-lived intangible assets, gross	$ 6.4	4.2
Weighted average amortization period (Year)	2 years 1 month 6 days
LDC Network Access [Member]
Finite-lived intangible assets, gross	$ 10.5	$ 10.5
Weighted average amortization period (Year)	10 years