Note 5 - Fair Value Measurements - Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Securities available for sale, at fair value	$ 651,047	$ 656,852
Fair Value, Inputs, Level 1 [Member]
Securities available for sale, at fair value	0	0
Fair Value, Inputs, Level 2 [Member]
Securities available for sale, at fair value	651,047	656,852
Fair Value, Inputs, Level 3 [Member]
Securities available for sale, at fair value	0	0
Reported Value Measurement [Member]
Cash and due from banks	11,695	12,403
Interest-bearing deposits	42,966	59,026
Securities available for sale, at fair value	651,047	656,852
Restricted securities	929	941
Loans, net	846,315	844,519
Accrued interest receivable	6,007	6,001
Bank-owned life insurance	43,551	43,312
Interest rate loan contracts	2
Deposits	1,511,452	1,542,725
Accrued interest payable	314	106
Interest rate loan contracts	2
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	11,695	12,403
Interest-bearing deposits	42,966	59,026
Securities available for sale, at fair value	0	0
Restricted securities	0	0
Loans, net	0	0
Accrued interest receivable	0	0
Bank-owned life insurance	0	0
Interest rate loan contracts	0
Deposits	0	0
Accrued interest payable	0	0
Interest rate loan contracts	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and due from banks	0	0
Interest-bearing deposits	0	0
Securities available for sale, at fair value	651,047	656,852
Restricted securities	929	941
Loans, net	0	0
Accrued interest receivable	6,007	6,001
Bank-owned life insurance	43,551	43,312
Interest rate loan contracts	0
Deposits	1,385,881	1,475,096
Accrued interest payable	314	106
Interest rate loan contracts	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and due from banks	0	0
Interest-bearing deposits	0	0
Securities available for sale, at fair value	0	0
Restricted securities	0	0
Loans, net	803,330	781,749
Accrued interest receivable	0	0
Bank-owned life insurance	0	0
Interest rate loan contracts	2
Deposits	125,931	67,542
Accrued interest payable	0	$ 0
Interest rate loan contracts	$ 2