Note 3 - Investment Securities - Investment Securities Continuous Unrealized Loss Position (Details) $ in Thousands	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Number of investment positions - less than twelve months, available for sale	59	278
Fair value - less than twelve months, available for sale	$ 56,837	$ 181,760
Gross unrealized losses - less than twelve months, available for sale	$ 864	$ 10,821
Number of investment positions - more than twelve months , available for sale	379	187
Fair value - more than twelve months, available for sale	$ 370,852	$ 258,858
Gross unrealized losses - more than twelve months, available for sale	$ 37,465	$ 36,023
Number of investment positions, available for sale	438	465
Fair value, available for sale	$ 427,689	$ 440,618
Gross unrealized losses, available for sale	38,329	$ 46,844
Number of investment positions - less than twelve months, held to maturity		3
Fair value - less than twelve months, held to maturity		$ 3,779
Gross unrealized losses - less than twelve months, held to maturity		1,221
Fair value - more than twelve months, held to maturity	5,296	1,532
Gross unrealized losses - more than twelve months, held to maturity	$ 1,704	$ 468
Number of investment positions, held to maturity	4	4
Fair value, held to maturity	$ 5,296	$ 5,311
Gross unrealized losses, held to maturity	1,704	1,689
Gross unrealized losses, held to maturity	$ 1,704	$ 1,689
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Number of investment positions - less than twelve months, available for sale	4	69
Fair value - less than twelve months, available for sale	$ 3,589	$ 27,561
Gross unrealized losses - less than twelve months, available for sale	$ 120	$ 2,214
Number of investment positions - more than twelve months , available for sale	93	28
Fair value - more than twelve months, available for sale	$ 78,717	$ 56,303
Gross unrealized losses - more than twelve months, available for sale	$ 9,174	$ 8,979
Agency Collateralized Mortgage Obligations [Member]
Number of investment positions - less than twelve months, available for sale	3	23
Fair value - less than twelve months, available for sale	$ 2,604	$ 6,287
Gross unrealized losses - less than twelve months, available for sale	$ 62	$ 336
Number of investment positions - more than twelve months , available for sale	22	3
Fair value - more than twelve months, available for sale	$ 3,557	$ 257
Gross unrealized losses - more than twelve months, available for sale	$ 161	$ 13
US Government Agencies Debt Securities [Member]
Number of investment positions - less than twelve months, available for sale	6	15
Fair value - less than twelve months, available for sale	$ 16,797	$ 35,079
Gross unrealized losses - less than twelve months, available for sale	$ 221	$ 1,314
Number of investment positions - more than twelve months , available for sale	52	45
Fair value - more than twelve months, available for sale	$ 121,382	$ 102,902
Gross unrealized losses - more than twelve months, available for sale	$ 10,274	$ 11,848
US Treasury and Government [Member]
Number of investment positions - less than twelve months, available for sale	10	17
Fair value - less than twelve months, available for sale	$ 16,734	$ 31,615
Gross unrealized losses - less than twelve months, available for sale	$ 266	$ 997
Number of investment positions - more than twelve months , available for sale	20	13
Fair value - more than twelve months, available for sale	$ 63,078	$ 47,117
Gross unrealized losses - more than twelve months, available for sale	$ 2,561	$ 2,917
US States and Political Subdivisions Debt Securities [Member]
Number of investment positions - less than twelve months, available for sale	36	154
Fair value - less than twelve months, available for sale	$ 17,113	$ 81,218
Gross unrealized losses - less than twelve months, available for sale	$ 195	$ 5,960
Municipal Notes [Member]
Number of investment positions - more than twelve months , available for sale	192	98
Fair value - more than twelve months, available for sale	$ 104,118	$ 52,279
Gross unrealized losses - more than twelve months, available for sale	$ 15,295	$ 12,266
Corporate Note Securities [Member]
Number of investment positions - less than twelve months, held to maturity	4	3
Fair value - less than twelve months, held to maturity	$ 5,296	$ 3,779
Gross unrealized losses - less than twelve months, held to maturity	$ 1,704	$ 1,221
Number of investment positions - more than twelve months, held to maturity	4	1
Fair value - more than twelve months, held to maturity		$ 1,532
Gross unrealized losses - more than twelve months, held to maturity		$ 468