Note 8 - Fair Values of Financial Instruments - Fair Value by Balance Sheet Grouping (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Available-for-sale securities, fair value	$ 40,572,382	$ 33,428,658
Reported Value Measurement [Member]
Cash and due from banks	6,830,000	6,374,000
Interest-bearing deposits with banks	8,835,000	5,400,000
Available-for-sale securities, fair value	40,572,000	33,429,000
Loans held for sale, at fair value	1,607,000
Loans held for investment, net	299,234,000	282,790,000
Stock in financial institutions	3,993,000	3,910,000
Demand deposits, savings and NOW deposits	215,443,000	187,700,000
Time deposits	80,094,000	77,359,000
Federal Home Loan Bank advances	40,000,000	67,000,000
Reported Value Measurement [Member] \| Discontinued Operations [Member]
Loans held for sale, at fair value	191,000	26,884,000
Reported Value Measurement [Member] \| Discontinued Operations [Member] \| Interest Rate Lock Commitments [Member]
Derivative IRLC's, fair value disclosure		381,000
Reported Value Measurement [Member] \| Discontinued Operations [Member] \| Forward Contracts [Member]
Derivative IRLC's, fair value disclosure		(154,000)
Estimate of Fair Value Measurement [Member]
Cash and due from banks	6,830,000	6,374,000
Interest-bearing deposits with banks	8,835,000	5,400,000
Available-for-sale securities, fair value	40,572,000	33,429,000
Loans held for sale, at fair value	1,607,000
Loans held for investment, net	303,476,000	283,466,000
Stock in financial institutions	3,993,000	3,910,000
Demand deposits, savings and NOW deposits	207,863,000	172,049,000
Time deposits	80,540,000	77,688,000
Federal Home Loan Bank advances	40,105,000	66,653,000
Estimate of Fair Value Measurement [Member] \| Discontinued Operations [Member]
Loans held for sale, at fair value	191,000	26,884,000
Estimate of Fair Value Measurement [Member] \| Discontinued Operations [Member] \| Interest Rate Lock Commitments [Member]
Derivative IRLC's, fair value disclosure		381,000
Estimate of Fair Value Measurement [Member] \| Discontinued Operations [Member] \| Forward Contracts [Member]
Derivative IRLC's, fair value disclosure		(154,000)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	6,830,000	6,374,000
Interest-bearing deposits with banks	8,835,000	5,400,000
Available-for-sale securities, fair value	0	0
Loans held for sale, at fair value
Loans held for investment, net		0
Stock in financial institutions	0	0
Demand deposits, savings and NOW deposits	207,863,000	172,049,000
Time deposits		0
Federal Home Loan Bank advances		0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Discontinued Operations [Member]
Loans held for sale, at fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Discontinued Operations [Member] \| Interest Rate Lock Commitments [Member]
Derivative IRLC's, fair value disclosure
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Discontinued Operations [Member] \| Forward Contracts [Member]
Derivative IRLC's, fair value disclosure
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and due from banks	0	0
Interest-bearing deposits with banks	0	0
Available-for-sale securities, fair value	40,572,000	33,429,000
Loans held for sale, at fair value	1,607,000
Loans held for investment, net		0
Stock in financial institutions	3,993,000	3,910,000
Demand deposits, savings and NOW deposits		0
Time deposits	80,540,000	77,688,000
Federal Home Loan Bank advances	40,105,000	66,653,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Discontinued Operations [Member]
Loans held for sale, at fair value	191,000	26,884,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Discontinued Operations [Member] \| Interest Rate Lock Commitments [Member]
Derivative IRLC's, fair value disclosure
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Discontinued Operations [Member] \| Forward Contracts [Member]
Derivative IRLC's, fair value disclosure		(154,000)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and due from banks	0	0
Interest-bearing deposits with banks	0	0
Available-for-sale securities, fair value	0	0
Loans held for sale, at fair value
Loans held for investment, net	303,476,000	283,466,000
Stock in financial institutions	0	0
Demand deposits, savings and NOW deposits		0
Time deposits		0
Federal Home Loan Bank advances		0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Discontinued Operations [Member]
Loans held for sale, at fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Discontinued Operations [Member] \| Interest Rate Lock Commitments [Member]
Derivative IRLC's, fair value disclosure		381,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Discontinued Operations [Member] \| Forward Contracts [Member]
Derivative IRLC's, fair value disclosure

Fair value portion of cash and due from banks.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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

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