Note 18 - Preferred Stock (Details Textual) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Apr. 30, 2021	Dec. 31, 2023	Dec. 31, 2022
Preferred Stock, Shares Issued (in shares)		1,500	1,500
Preferred Stock, Par or Stated Value Per Share (in dollars per share)		$ 1	$ 1
Series 2021 Fixed-Rate Noncumulative Preferred Stock [Member]
Preferred Stock, Shares Issued (in shares)	1,500
Preferred Stock, Value, Outstanding	$ 15
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 1
Preferred Stock, Liquidation Preference Per Share (in dollars per share)	$ 10,000
Preferred Stock, Dividend Rate, Percentage	6.00%