Note 5 - Derivatives and Other Hedging Instruments - Schedule of Interest Rate Swaps (Details) - Interest Rate Swap [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Notional amount	$ 3,516.8	$ 2,326.5
Average fixed pay rate	2.78%	2.24%
Average receive rate	4.54%	5.45%
Average maturity (Year)	5 years 6 months	5 years 10 months 24 days
One to Five Years [Member]
Notional amount	$ 1,450.0	$ 500.0
Average fixed pay rate	1.69%	0.84%
Average receive rate	4.58%	5.64%
Average maturity (Year)	3 years 4 months 24 days	2 years 8 months 12 days
More Than Five Years [Member]
Notional amount	$ 2,066.8	$ 1,826.5
Average fixed pay rate	3.55%	2.62%
Average receive rate	4.52%	5.40%
Average maturity (Year)	7 years	6 years 9 months 18 days