Note 12 - Derivative Financial Instruments - Derivative Instruments (Details) - Interest Expense [Member] - Designated as Hedging Instrument [Member] - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Interest Rate Swap [Member]
Derivative gain (loss)	$ 246,488	$ 122,537	$ 484,899	$ 162,378
Interest Rate Swap - Subordinated Debentures [Member]
Derivative gain (loss)	$ 64,508	$ 38,590	$ 127,470	$ 60,031

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=125515794&loc=SL5618551-113959

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