Note 5 - Loans (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Servicing Asset, Total	$ 181,400,000	$ 141,500,000
Impaired Financing Receivable, Recorded Investment	68,854,000	65,846,000
Impaired Financing Receivable, Average Recorded Investment	71,371,000	72,740,000
Impaired Financing Receivable, Interest Income, Accrual Method	$ 435,000	$ 1,074,000	$ 1,000,000.0
Percentage Of Charge Off To Contractual Balances For Impaired Loans	14.10%	10.70%
Financing Receivables, Impaired, Troubled Debt Restructuring, Specific Reserve	$ 427,000	$ 0	0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	0
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend	$ 0
Minimum [Member]
Period Loan Is In Payment Default (Day)	60 days
Maximum [Member]
Period Loan Is In Payment Default (Day)	90 days
Nonaccrual Loans [Member]
Impaired Financing Receivable, Recorded Investment	$ 68,900,000	65,800,000
Accruing Troubled Debt Restructuring [Member]
Financing Receivable, Troubled Debt Restructuring	15,100,000	12,800,000
Financing Receivables, Impaired, Troubled Debt Restructuring, Specific Reserve	0	7,000
Non-accruing Troubled Debt Restructuring [Member]
Financing Receivable, Troubled Debt Restructuring	6,300,000	8,200,000
Financing Receivables, Impaired, Troubled Debt Restructuring, Specific Reserve	427,000	3,000
Residential Portfolio Segment [Member]
Servicing Asset, Total	80,200,000	92,100,000
Repossessed Assets, Total	456,000	2,000,000.0
Commercial Real Estate Portfolio Segment [Member]
Servicing Asset, Total	51,600,000	17,000,000.0
Impaired Financing Receivable, Average Recorded Investment	28,983,000	38,047,000
Impaired Financing Receivable, Interest Income, Accrual Method	405,000	1,044,000
Commercial Construction Loans [Member]
Servicing Asset, Total	2,500,000	30,100,000
Commercial Portfolio Segment [Member]
Servicing Asset, Total	47,100,000	2,300,000
Impaired Financing Receivable, Average Recorded Investment	28,109,000	21,453,000
Impaired Financing Receivable, Interest Income, Accrual Method	4,000	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Specific Reserve	427,000	0	$ 0
Real Estate Loan [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	13,070,000,000.00	11,540,000,000
Commercial Loans [Member]
Loans Pledged with Federal Reserve Bank	$ 583,000	$ 773,000,000

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Carrying amount as of the balance sheet date of all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings or defeasance; includes real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts.

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