Note 2 - INVESTMENT SECURITIES - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Securities HTM:
Securities held to maturity, due in one year or less, amortized cost	$ 1,907
Securities held to maturity, due in one year or less, fair value	1,882
Securities held to maturity, due after one year through five years, amortized cost	27,159
Securities held to maturity, due after one year through five years, fair value	27,700
Securities held to maturity, due after five years, amortized cost	586,229
Securities held to maturity, due after five years, fair value	495,237
Securities HTM, Amortized cost	615,295	$ 587,322
Securities held to maturity, fair value	524,819	535,636
Securities AFS:
Securities available for sale, due in one year or less, amortized cost	3,160
Securities available for sale, Due in one year or less, fair value	3,146
Securities available for sale, due after one year through five years, amortized cost	14,338
Securities available for sale, Due after one year through five years, fair value	12,239
Securities available for sale, due after five years, amortized cost	255,481
Securities available for sale, due after five years, fair value	191,622
Securities available for sale, single maturity, amortized cost	272,979
Securities available for sale, single maturity, fair value	207,007
Securities AFS, Amortized Cost	355,638	400,511
Available-for-sale Securities, Debt Securities, Total	281,279	340,960
Callable Securities [Member]
Securities AFS:
Securities AFS, Amortized Cost	251,324
Available-for-sale Securities, Debt Securities, Total	188,512
Municipal securities.
Securities HTM:
Securities HTM, Amortized cost	614,245	586,272
Securities held to maturity, fair value	523,795	534,586
Securities AFS:
Securities AFS, Amortized Cost	207,318	239,812
Available-for-sale Securities, Debt Securities, Total	149,772	193,178
Municipal securities. | Callable Securities [Member]
Securities HTM:
Securities held to maturity, callable, amortized cost	230,493
Securities held to maturity, callable, fair value	194,222
Securities AFS:
Securities available for sale, callable, amortized cost	205,747
Securities available for sale, callable, fair value	148,235
Asset-backed securities
Securities AFS:
Securities AFS, Amortized Cost	16,226	18,885
Available-for-sale Securities, Debt Securities, Total	16,326	18,728
Securities available for sale, callable, amortized cost	16,226
Securities available for sale, callable, fair value	16,326
Residential mortgage-backed and related securities
Securities AFS:
Securities AFS, Amortized Cost	66,433	73,438
Available-for-sale Securities, Debt Securities, Total	57,946	66,215
Securities available for sale, callable, amortized cost	66,433
Securities available for sale, callable, fair value	57,946
Other securities
Securities HTM:
Securities HTM, Amortized cost	1,050	1,050
Securities held to maturity, fair value	1,024	1,050
Securities AFS:
Securities AFS, Amortized Cost	46,531	48,631
Available-for-sale Securities, Debt Securities, Total	41,233	$ 45,858
Other securities | Callable Securities [Member]
Securities AFS:
Securities available for sale, callable, amortized cost	45,577
Securities available for sale, callable, fair value	$ 40,277