Note 2 - Investment Securities - Held to Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Securities held-to-maturity, carrying value	$ 207,980	$ 370,171
Securities held-to-maturity, gains	3	2
Securities held-to-maturity, losses	(20,712)	(28,816)
Securities held-to-maturity, fair value	187,271	341,357
US Treasury Securities and US Government Agencies Debt Securities [Member]
Securities held-to-maturity, carrying value	1,985	153,850
Securities held-to-maturity, gains	0	0
Securities held-to-maturity, losses	(40)	(741)
Securities held-to-maturity, fair value	1,945	153,109
US Government-sponsored Enterprises Debt Securities [Member]
Securities held-to-maturity, carrying value	23,380	25,395
Securities held-to-maturity, gains	0	0
Securities held-to-maturity, losses	(1,303)	(2,034)
Securities held-to-maturity, fair value	22,077	23,361
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Securities held-to-maturity, carrying value	182,615	190,926
Securities held-to-maturity, gains	3	2
Securities held-to-maturity, losses	(19,369)	(26,041)
Securities held-to-maturity, fair value	$ 163,249	$ 164,887