Note 9 - Fair Value Measurement - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Investment securities	$ 447,445	$ 489,181
Reported Value Measurement [Member]
Cash and cash equivalents	128,231	85,655
Investment securities	447,445	489,181
Loans, net	966,141	948,604
FHLB stock	6,234	6,234
FRB Stock	1,367	1,371
Deposits	1,299,688	1,333,655
Repurchase agreements	19,331	23,054
Borrowings	120,000	90,000
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	128,231	85,655
Investment securities	447,445	489,181
Loans, net	927,114	923,500
Deposits	1,299,344	1,334,314
Repurchase agreements	19,331	23,054
Borrowings	115,379	86,100
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	128,231	85,655
Loans, net	0
FHLB stock	0
FRB Stock	0
Deposits	1,209,013	1,242,003
Repurchase agreements	0
Borrowings	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities	447,445	489,181
Loans, net	0
FHLB stock	0
FRB Stock	0
Deposits	90,331	92,311
Repurchase agreements	19,331	23,054
Borrowings	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities	0
Loans, net	927,114	923,500
FHLB stock	0
FRB Stock	0
Deposits	0
Repurchase agreements	0
Borrowings	$ 115,379	$ 86,100