Note 4 - Loans Held for Investment, Net - Impaired Loans (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Impaired loans, with no related allowance recorded, recorded investment	$ 3,409,628	$ 3,505,288
Impaired loans, with no related allowance recorded, principal net of charge-offs,	3,409,628	3,505,288
Impaired loans, with no related allowance recorded, average recorded investment	3,462,850	3,530,021
Impaired loans, with related allowance recorded, recorded investment	0	0
Impaired loans, with an allowance recorded, principal net of charge-offs	0	0
Impaired loans, related allowance	0	0
Impaired loans, with an allowance recorded, average recorded investment	0	0
Impaired loans, fair value disclosure	3,409,628	3,505,288
Impaired loans, principal net of charge-offs	3,409,628	3,505,288
Impaired loans, average recorded investment	3,462,850	3,530,021
Impaired loans, fair value disclosure	3,409,628	3,505,288
Commercial Real Estate Portfolio Segment [Member]
Impaired loans, with no related allowance recorded, recorded investment	2,642,676	2,718,731
Impaired loans, with no related allowance recorded, principal net of charge-offs,	2,642,676	2,718,731
Impaired loans, with no related allowance recorded, average recorded investment	2,682,032	2,738,545
Impaired loans, related allowance	0
Impaired loans, fair value disclosure	2,642,676	2,718,731
Impaired loans, principal net of charge-offs	2,642,676	2,718,731
Impaired loans, average recorded investment	2,682,032	2,738,545
Impaired loans, fair value disclosure	2,642,676	2,718,731
One-to-four Family Residential Real Estate Portfolio Segment [Member]
Impaired loans, with no related allowance recorded, recorded investment	766,952	786,557
Impaired loans, with no related allowance recorded, principal net of charge-offs,	766,952	786,557
Impaired loans, with no related allowance recorded, average recorded investment	780,818	791,476
Impaired loans, related allowance	0
Impaired loans, fair value disclosure	766,952	786,557
Impaired loans, principal net of charge-offs	766,952	786,557
Impaired loans, average recorded investment	780,818	791,476
Impaired loans, fair value disclosure	766,952	786,557
Commercial and Industrial Portfolio Segment [Member]
Impaired loans, with no related allowance recorded, recorded investment
Impaired loans, with no related allowance recorded, principal net of charge-offs,
Impaired loans, with no related allowance recorded, average recorded investment
Impaired loans, related allowance
Impaired loans, fair value disclosure
Impaired loans, principal net of charge-offs
Impaired loans, average recorded investment
Impaired loans, fair value disclosure
Consumer and Other Portfolio Segment [Member]
Impaired loans, with no related allowance recorded, recorded investment
Impaired loans, with no related allowance recorded, principal net of charge-offs,
Impaired loans, with no related allowance recorded, average recorded investment
Impaired loans, related allowance
Impaired loans, fair value disclosure
Impaired loans, principal net of charge-offs
Impaired loans, average recorded investment
Impaired loans, fair value disclosure

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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-Subparagraph (c)(1)
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