FAIR VALUE MEASUREMENTS - carrying value and estimated fair value (Details) - USD ($)	Mar. 31, 2026	Dec. 31, 2025
Financial assets
Available-for-sale debt securities	$ 5,469,258	$ 5,538,692
Carrying Value
Financial assets
Cash and cash equivalents	7,992,250	6,428,668
Available-for-sale debt securities	5,469,258	5,538,692
Loans	91,576,207	92,555,694
Accrued interest receivable	443,592	424,559
Federal Home Loan Bank stock	599,500	599,500
Cash surrender value of bank owned life insurance	3,084,464	3,067,607
Mortgage servicing rights	41,295	49,498
Financial liabilities
Deposits	83,142,278	82,154,201
Advances from the FHLB	10,600,000	10,600,000
Advances by borrowers for taxes and insurance	360,962	582,076
Federal funds purchased		33,000
Accrued interest payable	69,163	42,629
Estimated Fair Value
Financial assets
Cash and cash equivalents	7,992,250	6,428,668
Available-for-sale debt securities	5,469,258	5,538,692
Loans	93,530,000	93,851,000
Accrued interest receivable	443,592	424,559
Federal Home Loan Bank stock	599,500	599,500
Cash surrender value of bank owned life insurance	3,084,464	3,067,607
Mortgage servicing rights	118,437	141,964
Financial liabilities
Deposits	78,409,000	78,365,000
Advances from the FHLB	10,626,136	10,659,337
Advances by borrowers for taxes and insurance	360,962	582,076
Federal funds purchased		33,000
Accrued interest payable	69,163	42,629
Estimated Fair Value \| Level 1
Financial assets
Cash and cash equivalents	7,992,250	6,428,668
Accrued interest receivable	443,592	424,559
Financial liabilities
Accrued interest payable	69,163	42,629
Estimated Fair Value \| Level 2
Financial assets
Available-for-sale debt securities	5,469,258	5,538,692
Financial liabilities
Advances from the FHLB	10,626,136	10,659,337
Advances by borrowers for taxes and insurance	360,962	582,076
Federal funds purchased		33,000
Estimated Fair Value \| Level 3
Financial assets
Loans	93,530,000	93,851,000
Federal Home Loan Bank stock	599,500	599,500
Cash surrender value of bank owned life insurance	3,084,464	3,067,607
Mortgage servicing rights	118,437	141,964
Financial liabilities
Deposits	$ 78,409,000	$ 78,365,000

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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 the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Amount excluding accrued interest, 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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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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Fair value portion of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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

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