Note 5 - Fair Value of Financial Instruments - Estimated Fair Value of Company's Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Securities available for sale	$ 118,564	$ 107,592
Loans receivable, net	670,297	596,392
Reported Value Measurement [Member]
Cash and cash equivalents	76,027	44,399
Securities available for sale	118,564	107,592
Equity securities	127	167
Loans held for sale	7,225	3,606
Loans receivable, net	670,297	596,392
Federal Home Loan Bank stock	932	854
Accrued interest receivable	4,236	2,251
Deposits	787,023	673,870
Accrued interest payable	225	420
Commitments to extend credit	266	14
Commitments to sell loans	(102)	(16)
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	76,027	44,399
Securities available for sale	118,564	107,592
Equity securities	127	167
Loans held for sale	7,225	3,606
Loans receivable, net	674,804	600,863
Federal Home Loan Bank stock	932	854
Accrued interest receivable	4,236	2,251
Deposits	787,975	673,945
Accrued interest payable	225	420
Commitments to extend credit	266	14
Commitments to sell loans	(102)	(16)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	76,027	44,399
Securities available for sale
Equity securities
Loans held for sale
Loans receivable, net
Federal Home Loan Bank stock
Accrued interest receivable
Deposits
Accrued interest payable
Commitments to extend credit
Commitments to sell loans
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents
Securities available for sale	118,564	107,592
Equity securities	127	167
Loans held for sale	7,225	3,606
Loans receivable, net	674,804	600,863
Federal Home Loan Bank stock	932	854
Accrued interest receivable	4,236	2,251
Deposits	787,975	673,945
Accrued interest payable	225	420
Commitments to extend credit
Commitments to sell loans
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents
Securities available for sale
Equity securities
Loans held for sale
Loans receivable, net
Federal Home Loan Bank stock
Accrued interest receivable
Deposits
Accrued interest payable
Commitments to extend credit
Commitments to sell loans
Portion at Other than Fair Value Measurement [Member]
Cash and cash equivalents
Securities available for sale
Equity securities
Loans held for sale
Loans receivable, net
Federal Home Loan Bank stock
Accrued interest receivable
Deposits
Accrued interest payable
Commitments to extend credit	191,522	178,804
Commitments to sell loans	$ 48,199	$ 10,098

Fair value portion of accrued interest payable.

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Fair value portion of accrued interest receivable.

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The face amount of financial liabilities related to commitments to sell, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-SubTopic 210
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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- Definition

Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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