Note 4 - Earnings Per Share (Details Textual) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Treasury Stock, Shares, Total (in shares)	1,582,813		1,582,813		1,441,811
Treasury Stock, Shares, Acquired (in shares)	45,638	165,058	141,002	346,103
Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance (in shares)	63,646	77,933	63,646	77,933
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)			50,620	57,400