Note 12 - Derivative Financial Instruments - Derivative Instruments (Details) - Interest Expense [Member] - Designated as Hedging Instrument [Member] - USD ($)	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Interest Rate Swap [Member]
Derivative gain (loss)	$ 238,411	$ 39,841
Interest Rate Swap - Subordinated Debentures [Member]
Derivative gain (loss)	$ 62,962	$ 21,441

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration