Note 3 - Investment Securities - Held to Maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Securities held-to-maturity, carrying value	$ 370,171	$ 439,837
Securities held-to-maturity, gains	2	1
Securities held-to-maturity, losses	(28,816)	(31,319)
Securities held-to-maturity, fair value	341,357	408,519
US Treasury Securities and US Government Agencies Debt Securities [Member]
Securities held-to-maturity, carrying value	153,850	203,259
Securities held-to-maturity, gains	0	0
Securities held-to-maturity, losses	(741)	(4,932)
Securities held-to-maturity, fair value	153,109	198,327
US Government-sponsored Enterprises Debt Securities [Member]
Securities held-to-maturity, carrying value	25,395	26,918
Securities held-to-maturity, gains	0	0
Securities held-to-maturity, losses	(2,034)	(2,457)
Securities held-to-maturity, fair value	23,361	24,461
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Securities held-to-maturity, carrying value	190,926	209,660
Securities held-to-maturity, gains	2	1
Securities held-to-maturity, losses	(26,041)	(23,930)
Securities held-to-maturity, fair value	$ 164,887	$ 185,731

Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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