Note 4 - Derivatives and Other Hedging Instruments - Schedule of Interest Rate Swaps (Details) - Interest Rate Swap [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Notional Amount	$ 1,400	$ 1,355
Average fixed pay rate	1.39%	0.79%
Average receive rate	4.41%	0.18%
Average maturity (Year)	5 years 7 months 6 days	5 years
Three to Five Years [Member]
Notional Amount	$ 500	$ 400
Average fixed pay rate	0.84%	1.16%
Average receive rate	4.75%	0.21%
Average maturity (Year)	3 years 8 months 12 days	7 years 3 months 18 days
More Than Five Years [Member]
Notional Amount	$ 900
Average fixed pay rate	1.70%
Average receive rate	4.23%
Average maturity (Year)	6 years 7 months 6 days
One To Three Years [Member]
Notional Amount		$ 955
Average fixed pay rate		0.64%
Average receive rate		0.16%
Average maturity (Year)		4 years