Note 9 - Income Taxes - Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Allowance for credit losses	$ 12,854,000	$ 6,633,000
Deferred compensation	5,903,000	5,758,000
Operating lease liability	3,214,000	3,427,000
State net operating loss	2,838,000	2,550,000
Deferred PPP loan fees	2,592,000	0
Accrued expenses	3,074,000	1,486,000
Investments in tax credit partnerships	935,000	655,000
Loans	562,000	501,000
Other assets	91,000	228,000
Write-downs and costs associated with other real estate owned	26,000	22,000
Total deferred tax assets	32,089,000	21,260,000
Property and equipment	1,116,000	1,054,000
Right-of-use operating lease asset	2,996,000	3,154,000
Securities	3,258,000	748,000
Loan costs	951,000	767,000
Mortgage servicing rights	637,000	299,000
Leases	224,000	266,000
Core deposit intangible	151,000	202,000
Other liabilities	343,000	183,000
Total deferred tax liabilities	9,676,000	6,673,000
Valuation allowance	(93,000)	(121,000)
Net deferred tax asset	$ 22,320,000	$ 14,466,000