Note 2 - Investment Securities - Investment Securities Continuous Unrealized Loss Position (Details) $ in Thousands	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Number of investment positions - less than twelve months, available for sale	405	122
Fair value - less than twelve months, available for sale	$ 366,098	$ 247,386
Gross unrealized losses - less than twelve months, available for sale	$ 32,534	$ 3,341
Number of investment positions - more than twelve months , available for sale	34	9
Fair value - more than twelve months, available for sale	$ 65,954	$ 17,990
Gross unrealized losses - more than twelve months, available for sale	$ 7,016	$ 456
Number of investment positions, available for sale	439	131
Fair value, available for sale	$ 432,052	$ 265,376
Gross unrealized losses, available for sale	$ 39,550	$ 3,797
Number of investment positions - less than twelve months, held to maturity	4
Fair value - less than twelve months, held to maturity	$ 6,276
Gross unrealized losses - less than twelve months, held to maturity	$ 724
Number of investment positions, held to maturity	4
Fair value, held to maturity	$ 6,276
Gross unrealized losses, held to maturity	$ 724
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Number of investment positions - less than twelve months, available for sale	91	23
Fair value - less than twelve months, available for sale	$ 84,065	$ 67,512
Gross unrealized losses - less than twelve months, available for sale	$ 8,048	$ 607
Number of investment positions - more than twelve months , available for sale	5	1
Fair value - more than twelve months, available for sale	$ 8,123	$ 1,357
Gross unrealized losses - more than twelve months, available for sale	$ 1,048	$ 28
US Government Agencies Debt Securities [Member]
Number of investment positions - less than twelve months, available for sale	39	39
Fair value - less than twelve months, available for sale	$ 86,629	$ 98,042
Gross unrealized losses - less than twelve months, available for sale	$ 5,759	$ 1,710
Number of investment positions - more than twelve months , available for sale	17	4
Fair value - more than twelve months, available for sale	$ 46,008	$ 13,676
Gross unrealized losses - more than twelve months, available for sale	$ 4,341	$ 324
Agency Collateralized Mortgage Obligations [Member]
Number of investment positions - less than twelve months, available for sale	29
Fair value - less than twelve months, available for sale	$ 8,007
Gross unrealized losses - less than twelve months, available for sale	$ 197
US Treasury and Government [Member]
Number of investment positions - less than twelve months, available for sale	23	11
Fair value - less than twelve months, available for sale	$ 68,544	$ 49,190
Gross unrealized losses - less than twelve months, available for sale	$ 2,612	$ 545
Number of investment positions - more than twelve months , available for sale	1
Fair value - more than twelve months, available for sale	$ 4,830
Gross unrealized losses - more than twelve months, available for sale	$ 164
US States and Political Subdivisions Debt Securities [Member]
Number of investment positions - less than twelve months, available for sale	223	49
Fair value - less than twelve months, available for sale	$ 118,853	$ 32,642
Gross unrealized losses - less than twelve months, available for sale	$ 15,918	$ 479
Municipal Notes [Member]
Number of investment positions - more than twelve months , available for sale	11	4
Fair value - more than twelve months, available for sale	$ 6,993	$ 2,957
Gross unrealized losses - more than twelve months, available for sale	$ 1,463	$ 104
Corporate Note Securities [Member]
Number of investment positions - less than twelve months, held to maturity	4
Fair value - less than twelve months, held to maturity	$ 6,276
Gross unrealized losses - less than twelve months, held to maturity	$ 724