Note 4 - Derivatives and Other Hedging Instruments - Schedule of Interest Rate Swaps (Details) - Interest Rate Swap [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Notional amount	$ 1,674	$ 1,400
Average fixed pay rate	1.72%	1.39%
Average receive rate	4.92%	4.41%
Average maturity (Year)	6 years 1 month 6 days	5 years 7 months 6 days
Three to Five Years [Member]
Notional amount	$ 500	$ 900
Average fixed pay rate	0.84%	1.70%
Average receive rate	5.02%	4.23%
Average maturity (Year)	3 years 6 months	6 years 7 months 6 days
More Than Five Years [Member]
Notional amount	$ 1,174
Average fixed pay rate	2.10%
Average receive rate	4.88%
Average maturity (Year)	7 years 2 months 12 days
One To Three Years [Member]
Notional amount		$ 500
Average fixed pay rate		0.84%
Average receive rate		4.75%
Average maturity (Year)		3 years 8 months 12 days