Note 4 - Securities - Securities in a Continuous Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Temporarily impaired securities, less than 12 months, fair value	$ 1,402	$ 2,500
Temporarily impaired securities, less than 12 months unrealized loss	121	27
Temporarily impaired securities, 12 months or more fair value	582,519	615,242
Temporarily impaired securities, 12 months or more unrealized loss	83,506	79,158
US Government Agencies Debt Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	0	0
Temporarily impaired securities, less than 12 months unrealized loss	0	0
Temporarily impaired securities, 12 months or more fair value	308,813	311,844
Temporarily impaired securities, 12 months or more unrealized loss	44,205	42,060
US States and Political Subdivisions Debt Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	882	884
Temporarily impaired securities, less than 12 months unrealized loss	120	1
Temporarily impaired securities, 12 months or more fair value	145,120	148,763
Temporarily impaired securities, 12 months or more unrealized loss	32,313	29,613
Commercial Mortgage-Backed Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	520	1,616
Temporarily impaired securities, less than 12 months unrealized loss	1	26
Temporarily impaired securities, 12 months or more fair value	121,951	147,922
Temporarily impaired securities, 12 months or more unrealized loss	6,119	6,698
Corporate Debt Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	0	0
Temporarily impaired securities, less than 12 months unrealized loss	0	0
Temporarily impaired securities, 12 months or more fair value	5,657	5,750
Temporarily impaired securities, 12 months or more unrealized loss	849	754
US Treasury Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	0	0
Temporarily impaired securities, less than 12 months unrealized loss	0	0
Temporarily impaired securities, 12 months or more fair value	978	963
Temporarily impaired securities, 12 months or more unrealized loss	$ 20	$ 33

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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