Note 3 - Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans (Details) - USD ($)		Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, before Allowance for Credit Loss		$ 4,104,376,000	$ 3,916,619,000
Loans past due 90 days or more still accruing interest		0	0
Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		3,218,831,000	3,131,830,000
Loans past due 90 days or more still accruing interest		0	0
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss		1,166,187,000	1,185,083,000
Loans past due 90 days or more still accruing interest		0	0
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss		72,921,000	61,873,000
Loans past due 90 days or more still accruing interest		0	0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		671,083,000	639,192,000
Loans past due 90 days or more still accruing interest		0	0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss	[1]	1,000,411,000	979,214,000
Loans past due 90 days or more still accruing interest		0	0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, before Allowance for Credit Loss	[1]	308,229,000	266,468,000
Loans past due 90 days or more still accruing interest		0	0
Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		885,545,000	784,789,000
Loans past due 90 days or more still accruing interest		0	0
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss		854,175,000	755,036,000
Loans past due 90 days or more still accruing interest		0	0
Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss		31,370,000	29,753,000
Loans past due 90 days or more still accruing interest		0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, before Allowance for Credit Loss		685,000	1,349,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		4,000	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss		4,000	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		681,000	1,349,000
Financial Asset, 30 to 59 Days Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss		680,000	1,334,000
Financial Asset, 30 to 59 Days Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss		1,000	15,000
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, before Allowance for Credit Loss		499,000	6,042,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		0	5,953,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss		0	5,705,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	248,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		499,000	89,000
Financial Asset, 60 to 89 Days Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss		499,000	88,000
Financial Asset, 60 to 89 Days Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss		0	1,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, before Allowance for Credit Loss		451,000	365,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		319,000	249,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss		249,000	249,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		70,000	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		132,000	116,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss		132,000	116,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Past Due [Member]
Financing Receivable, before Allowance for Credit Loss		1,635,000	7,756,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		323,000	6,202,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss		253,000	5,954,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		70,000	248,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, before Allowance for Credit Loss		0	0
Financial Asset, Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		1,312,000	1,554,000
Financial Asset, Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss		1,311,000	1,538,000
Financial Asset, Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss		1,000	16,000
Financial Asset, Not Past Due [Member]
Financing Receivable, before Allowance for Credit Loss		4,102,741,000	3,908,863,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		3,218,508,000	3,125,628,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss		1,165,934,000	1,179,129,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss		72,921,000	61,873,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		671,013,000	638,944,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss		1,000,411,000	979,214,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, before Allowance for Credit Loss		308,229,000	266,468,000
Financial Asset, Not Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss		884,233,000	783,235,000
Financial Asset, Not Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss		852,864,000	753,498,000
Financial Asset, Not Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss		$ 31,369,000	$ 29,737,000

[1] We have made certain reclassifications of how multi-family construction loans are disaggregated by loan segment. The table above reflects an increase of $54.5 million in Real Estate – Multi-Family and Residential Rental loans and a corresponding decrease in Real Estate – Non-Owner Occupied loans as of December 31, 2022. All the tables that follow have been adjusted to reflect the reclassifications as of the applicable dates.