Note 3 - Investment Securities - Schedule of Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Due within one year or less, Held-to-maturity, Amortized Cost	$ 11,648
Due within one year or less, Held-to-maturity, Fair Value	11,504
Due within one year or less, Available-for-sale, Amortized Cost	0
Due within one year or less, Available-for-sale, Fair Value	0
Due after one year through five years, Held-to-maturity, Amortized Cost	57,043
Due after one year through five years, Held-to-maturity, Fair Value	54,041
Due after one year through five years, Available-for-sale, Amortized Cost	4,777
Due after one year through five years, Available-for-sale, Fair Value	4,723
Due after five years through ten years, Held-to-maturity, Amortized Cost	37,390
Due after five years through ten years, Held-to-maturity, Fair Value	34,026
Due after five years through ten years, Available-for-sale, Amortized Cost	49,998
Due after five years through ten years, Available-for-sale, Fair Value	46,254
Due after 10 years, Held-to-maturity, Amortized Cost	7,404
Due after 10 years, Held-to-maturity, Fair Value	6,695
Due after 10 years, Available-for-sale, Amortized Cost	201
Due after 10 years, Available-for-sale, Fair Value	200
Held-to-maturity, Amortized cost	113,485
Held-to-maturity, Fair Value	106,266
Available-for-sale, Amortized Cost	54,976
Available-for-sale, Fair Value	51,177
Total investment securities	259,351
Total investment securities, Held-to-maturity, Fair Value	230,597	$ 236,986
Total investment securities, Available-for-sale, Amortized Cost	603,221	686,556
Total investment securities, Available-for-sale, Fair Value	531,014	588,053
Residential Mortgage-Backed Securities [Member]
Residential agency, Held-to-maturity, Amortized Cost	145,866
Residential agency, Held-to-maturity, Fair Value	124,331
Residential agency, Available-for-sale, Amortized Cost	548,245
Residential agency, Available-for-sale, Fair Value	479,837
Total investment securities, Held-to-maturity, Fair Value	124,331	129,001
Total investment securities, Available-for-sale, Fair Value	$ 479,837	$ 503,706