Note 4 - Earnings Per Share (Details Textual) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)	13,500	14,500	13,500	14,500	14,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance (in dollars per share)	$ 8.78	$ 8.78	$ 8.78	$ 8.78	$ 8.78
Treasury Stock, Shares, Ending Balance (in shares)	929,362	807,824	929,362	807,824	871,162
Treasury Stock, Shares, Acquired (in shares)		35,494	58,200	35,494
Employee Stock Option and Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	73,147	0	0	0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)	84,688	61,334	84,688	61,334	61,040