Note 3 - Securities - Available for Sale Securities in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Total, fair value	$ 604,414	$ 510,918
Total, unrealized loss	71,066	7,258
Less than 12 months, fair value	187,643	456,863
Less than 12 months, unrealized loss	13,616	5,194
12 months or more, fair value	416,771	54,055
12 months or more, unrealized loss	57,450	2,064
US Treasury Securities [Member]
Total, fair value	139,427	149,577
Total, unrealized loss	12,606	1,174
Less than 12 months, fair value	10,824	149,577
Less than 12 months, unrealized loss	915	1,174
12 months or more, fair value	128,603	0
12 months or more, unrealized loss	11,691	0
US Government-sponsored Enterprises Debt Securities [Member]
Total, fair value	82,958	73,640
Total, unrealized loss	7,019	931
Less than 12 months, fair value	29,204	63,042
Less than 12 months, unrealized loss	1,920	512
12 months or more, fair value	53,754	10,598
12 months or more, unrealized loss	5,099	419
Collateralized Mortgage-Backed Securities [Member]
Total, fair value	293,929	253,444
Total, unrealized loss	42,301	4,525
Less than 12 months, fair value	96,758	213,292
Less than 12 months, unrealized loss	7,245	3,014
12 months or more, fair value	197,171	40,152
12 months or more, unrealized loss	35,056	1,511
US States and Political Subdivisions Debt Securities [Member]
Total, fair value	60,629	26,646
Total, unrealized loss	5,312	488
Less than 12 months, fair value	31,866	23,341
Less than 12 months, unrealized loss	980	354
12 months or more, fair value	28,763	3,305
12 months or more, unrealized loss	4,332	134
Corporate Debt Securities [Member]
Total, fair value	27,471	7,611
Total, unrealized loss	3,828	140
Less than 12 months, fair value	18,991	7,611
Less than 12 months, unrealized loss	2,556	140
12 months or more, fair value	8,480	0
12 months or more, unrealized loss	$ 1,272	$ 0