Note 3 - Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans (Details) - USD ($)		Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, before Allowance for Credit Loss, Total		$ 3,555,790,000	$ 3,453,459,000
Loans past due 90 days or more still accruing interest		0	155,000
Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		3,004,562,000	2,950,424,000
Loans past due 90 days or more still accruing interest		0	155,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss, Total	[1]	1,153,814,000	1,137,419,000
Loans past due 90 days or more still accruing interest		0	155,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, before Allowance for Credit Loss, Total		52,693,000	43,239,000
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, Total		582,732,000	565,758,000
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, Total		1,007,361,000	1,027,415,000
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, Total		207,962,000	176,593,000
Loans past due 90 days or more still accruing interest		0	0
Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		551,228,000	503,035,000
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, Total		522,556,000	442,547,000
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, Total	[2]	28,672,000	60,488,000
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, Total		1,779,000	1,424,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		1,195,000	27,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss, Total		0	14,000
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, Total		0	13,000
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, Total		1,195,000	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, Total		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, Total		0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		584,000	1,397,000
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, Total		567,000	1,265,000
Financial Asset, 30 to 59 Days Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss, Total		17,000	132,000
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, before Allowance for Credit Loss, Total		89,000	243,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss, Total		0	0
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, Total		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, Total		0	0
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, Total		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, Total		0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		89,000	243,000
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, Total		89,000	241,000
Financial Asset, 60 to 89 Days Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss, Total		0	2,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, before Allowance for Credit Loss, Total		154,000	295,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		0	193,000
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, Total		0	193,000
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, Total		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, Total		0	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, Total		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, Total		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, Total		154,000	102,000
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, Total		154,000	82,000
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, Total		0	20,000
Financial Asset, Past Due [Member]
Financing Receivable, before Allowance for Credit Loss, Total		2,022,000	1,962,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		1,195,000	220,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss, Total		0	207,000
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, Total		0	13,000
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss, Total		1,195,000	0
Financial Asset, Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss, Total		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, Total		0	0
Financial Asset, Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		827,000	1,742,000
Financial Asset, Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss, Total		810,000	1,588,000
Financial Asset, Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss, Total		17,000	154,000
Financial Asset, Not Past Due [Member]
Financing Receivable, before Allowance for Credit Loss, Total		3,553,768,000	3,451,497,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		3,003,367,000	2,950,204,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Financing Receivable, before Allowance for Credit Loss, Total		1,153,814,000	1,137,212,000
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, Total		52,693,000	43,226,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss, Total		581,537,000	565,758,000
Financial Asset, Not Past Due [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, before Allowance for Credit Loss, Total		1,007,361,000	1,027,415,000
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, Total		207,962,000	176,593,000
Financial Asset, Not Past Due [Member] | Retail Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss, Total		550,401,000	501,293,000
Financial Asset, Not Past Due [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Financing Receivable, before Allowance for Credit Loss, Total		521,746,000	440,959,000
Financial Asset, Not Past Due [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Financing Receivable, before Allowance for Credit Loss, Total		$ 28,655,000	$ 60,334,000

[1] For March 31, 2022, and December 31, 2021, includes $12.2 million and $40.1 million in loans originated under the Paycheck Protection Program, respectively.

[2] In conjunction with the adoption of the CECL methodology effective January 1, 2022, home equity lines of credit were reclassified to 1-4 family mortgage loans from other consumer loans. Home equity lines of credit totaled $31.9 million and $29.5 million as of March 31, 2022 and December 31, 2021, respectively.