Note 2 - Securities - Securities with Unrealized Losses Aggregated by Investment Category and Time with Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Less than 12 months, Fair Value	$ 153,118	$ 515,182
Less than 12 months, Unrealized Losses	15,751	10,599
More than 12 months, Fair Value	375,245	102,211
More than 12 months, Unrealized Losses	73,290	4,196
Total, Fair Value	528,363	617,393
Total, Unrealized Losses	89,041	14,795
US Treasury and Government [Member]
Less than 12 months, Fair Value	0	0
Less than 12 months, Unrealized Losses	0	0
More than 12 months, Fair Value	0	0
More than 12 months, Unrealized Losses	0	0
Total, Fair Value	0	0
Total, Unrealized Losses	0	0
US Treasury Securities [Member]
Less than 12 months, Fair Value	0	89,958
Less than 12 months, Unrealized Losses	0	1,311
More than 12 months, Fair Value	78,204	0
More than 12 months, Unrealized Losses	12,606	0
Total, Fair Value	78,204	89,958
Total, Unrealized Losses	12,606	1,311
US States and Political Subdivisions Debt Securities [Member]
Less than 12 months, Fair Value	89,158	130,001
Less than 12 months, Unrealized Losses	12,612	3,253
More than 12 months, Fair Value	140,390	15,237
More than 12 months, Unrealized Losses	34,939	856
Total, Fair Value	229,548	145,238
Total, Unrealized Losses	47,551	4,109
Collateralized Mortgage-Backed Securities [Member]
Less than 12 months, Fair Value	63,249	261,560
Less than 12 months, Unrealized Losses	3,093	5,709
More than 12 months, Fair Value	144,318	86,974
More than 12 months, Unrealized Losses	25,047	3,340
Total, Fair Value	207,567	348,534
Total, Unrealized Losses	28,140	9,049
Corporate Debt Securities [Member]
Less than 12 months, Fair Value	711	17,369
Less than 12 months, Unrealized Losses	46	233
More than 12 months, Fair Value	0	0
More than 12 months, Unrealized Losses	0	0
Total, Fair Value	711	17,369
Total, Unrealized Losses	46	233
Asset-Backed Securities [Member]
Less than 12 months, Fair Value	0	16,294
Less than 12 months, Unrealized Losses	0	93
More than 12 months, Fair Value	12,333	0
More than 12 months, Unrealized Losses	698	0
Total, Fair Value	12,333	16,294
Total, Unrealized Losses	$ 698	$ 93

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
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