Note 3 - INVESTMENT SECURITIES - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Securities held to maturity:
Securities held to maturity, due in one year or less, amortized cost	$ 3,061
Securities held to maturity, due in one year or less, fair value	3,046
Securities held to maturity, due after one year through five years, amortized cost	15,199
Securities held to maturity, due after one year through five years, fair value	14,862
Securities held to maturity, due after five years, amortized cost	521,651
Securities held to maturity, due after five years, fair value	493,539
Securities held to maturity, amortized cost	539,911
Securities held to maturity, fair value	511,447	$ 522,297
Securities available for sale:
Securities available for sale, due in one year or less, amortized cost	8,558
Securities available for sale, Due in one year or less, fair value	8,535
Securities available for sale, due after one year through five years, amortized cost	3,760
Securities available for sale, Due after one year through five years, fair value	3,705
Securities available for sale, due after five years, amortized cost	300,063
Securities available for sale, due after five years, fair value	239,023
Securities available for sale, single maturity, amortized cost	312,381
Securities available for sale, single maturity, fair value	251,263
Debt Securities, Available-for-sale, Amortized Cost	408,715	329,994
Available-for-sale Securities, Debt Securities, Total	339,737	337,830
Callable Securities [Member]
Securities available for sale:
Debt Securities, Available-for-sale, Amortized Cost	283,382
Available-for-sale Securities, Debt Securities, Total	225,218
Municipal securities.
Securities held to maturity:
Securities held to maturity, fair value	510,403	521,248
Securities available for sale:
Debt Securities, Available-for-sale, Amortized Cost	241,292	163,253
Available-for-sale Securities, Debt Securities, Total	185,343	168,266
Municipal securities. | Callable Securities [Member]
Securities held to maturity:
Securities held to maturity, callable, amortized cost	305,743
Securities held to maturity, callable, fair value	295,096
Securities available for sale:
Securities available for sale, callable, amortized cost	237,105
Securities available for sale, callable, fair value	181,201
Asset-backed securities
Securities available for sale:
Debt Securities, Available-for-sale, Amortized Cost	19,654	26,372
Available-for-sale Securities, Debt Securities, Total	19,630	27,124
Securities available for sale, callable, amortized cost	19,654
Securities available for sale, callable, fair value	19,630
Residential mortgage-backed and related securities
Securities available for sale:
Debt Securities, Available-for-sale, Amortized Cost	76,680	92,431
Available-for-sale Securities, Debt Securities, Total	68,844	94,323
Securities available for sale, callable, amortized cost	76,680
Securities available for sale, callable, fair value	68,844
Other Securities
Securities held to maturity:
Securities held to maturity, fair value	1,044	1,049
Securities available for sale:
Debt Securities, Available-for-sale, Amortized Cost	47,700	24,568
Available-for-sale Securities, Debt Securities, Total	45,393	$ 24,789
Other Securities | Callable Securities [Member]
Securities available for sale:
Securities available for sale, callable, amortized cost	46,277
Securities available for sale, callable, fair value	$ 44,017