Note 16 - Employee Benefit Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Plan Eligibility (Month)	90 days
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	3.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 197,214	$ 285,618
Employee Stock Purchase Plan, Percent of Wages Withheld, Maximum	10.00%
Employee Stock Purchase Plan, Max Annual Contribution by Employees	$ 10,000
Percent of Purchase Price to Company's Common Stock on Last Day of Offering Period	85.00%
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 106,775	$ 108,466
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)	9,209	19,641
Employee Stock Purchase Plan, Shares Authorized (in shares)	100,000
Employee Stock Purchase Plan, Employer Expense During Period	$ 31,748	$ 31,954