Note 10 - Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2023			2022			2021
Expected option life in years(1)		6.0			6.0			6.0
Expected stock price volatility percentage(2)		28	%		26	%		27	%
Risk-free interest rate percentage(3)		4.1	%		2.9	%		1.2	%
Expected dividend yield(4)		1.14	%		1.13	%		0.91	%
Fair value as of the date of grant	$	6.63		$	5.79		$	4.29

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Shares			Weighted- Average Exercise Price
Outstanding at December 31, 2022		915,391		$	15.84
Granted		39,000			21.44
Exercised		(106,941	)		11.30
Forfeited		(9,300	)		18.35
Outstanding at December 31, 2023		838,150		$	16.65
Exercisable at December 31, 2023		431,850		$	15.12

Schedule of Nonvested Share Activity [Table Text Block]

	Shares			Weighted- Average Grant Date Fair Value		Weighted- Average Remaining Contractual Life (in Years)
Nonvested at December 31, 2022		544,150		$	4.62		5.5
Granted		39,000			6.63		6.6
Vested		(167,550	)		4.44		3.9
Forfeited		(9,300	)		5.01		5.2
Nonvested at December 31, 2023		406,300		$	4.88		5.0

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

	Shares			Weighted-Average Grant Date Fair Value
Nonvested at December 31, 2022		121,867		$	17.83
Granted		114,044			20.49
Vested		(47,511	)(1)		17.56
Nonvested at December 31, 2023		188,400		$	19.51