Note 2 - Investment Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Securities available for sale, amortized cost, due in one year or less	$ 7,605
Securities available for sale, fair value, due in one year or less	7,452
Securities held to maturity, amortized cost, due in one year or less	0
Securities held to maturity, fair value, due in one year or less	0
Securities available for sale, amortized cost, due after one year through five years	227,390
Securities available for sale, fair value, due after one year through five years	214,814
Securities held to maturity, amortized cost, due after one year through five years	0
Securities held to maturity, fair value, due after one year through five years	0
Securities available for sale, amortized cost, due after five years through ten years	48,645
Securities available for sale, fair value, due after five years through ten years	45,648
Securities held to maturity, amortized cost, due after five years through ten years	2,000
Securities held to maturity, fair value, due after five years through ten years	1,796
Securities available for sale, amortized cost, due after ten years	103,798
Securities available for sale, fair value, due after ten years	89,390
Securities held to maturity, amortized cost, due after ten years	5,000
Securities held to maturity, fair value, due after ten years	4,480
Securities available for sale, amortized cost, single maturity	387,438
Securities available for sale, fair value, single maturity	357,304
Securities held to maturity, amortized cost, single maturity	7,000
Securities held to maturity, fair value, single maturity	6,276
Mortgage-backed securities and CMO, amortized cost	110,608
Mortgage-backed securities and CMO, fair value	101,316
Mortgage-backed securities and CMO, amortized cost	0
Mortgage-backed securities and CMO, fair value	0
Securities available for sale, amortized cost	498,046	$ 445,220
Securities available for sale, fair value	458,620	447,335
Securities held to maturity, amortized cost	7,000	2,000
Securities held to maturity, fair value	$ 6,276	$ 2,004