Note 10 - Deposits - Interest Expense on Deposits (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
NOW and Money Market accounts	$ 4,427,407	$ 2,394,549	$ 1,235,359
Savings accounts	105,592	58,384	55,094
Certificate accounts	2,524,098	1,309,629	1,002,872
Early withdrawal penalties	(33,811)	(10,997)	(9,343)
	$ 7,023,286	$ 3,751,565	$ 2,283,982

Aggregate amount of interest expense on all deposits.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.6)
-URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260

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- Definition

Early withdrawal penalties on domestic deposits which discourage customer withdrawal prior to maturity.

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- Definition

Interest expense incurred on all money market deposits.

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Interest expense incurred on all savings account deposits.

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- Definition

The aggregate interest expense incurred on time deposits, including certificates of deposits, in domestic offices.

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