Note 9 - Share-based Compensation (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 dividend yield at date of grant		2.13	%		3.39	%		2.15	%
Expected stock price volatility		35.12	%		35.52	%		34.85	%
Risk-free interest rate		3.61	%		2.33	%		0.91	%
Expected life of options (in years)		6.85			6.29			7.01

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

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms (Years)		Aggregate Intrinsic Value (In thousands)
Common Stock
Outstanding at December 31, 2022		581,286	$	32.86
Granted		96,359	$	40.55
Exercised		87,378	$	20.89
Forfeited		21,099	$	40.52
Outstanding at December 31, 2023		569,168	$	35.72		5.75	$	3,971
Exercisable at December 31, 2023		346,032	$	30.73		4.55	$	3,894

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value, Intrinsic Value of Exercised and Vested in Period, and Fair Value of Vested in Period [Table Text Block]

	2023		2022		2021
Weighted average grant date fair value of stock options granted	$	9.16	$	9.43	$	12.55
Intrinsic value of stock options exercised (in thousands)	$	2,037	$	648	$	3,535
Intrinsic value of stock options vested (in thousands)	$	3,894	$	4,369	$	4,805

Schedule of Nonvested Share Activity [Table Text Block]

	Common Stock Outstanding		Common Stock Weighted Average Grant Date Fair Value Per Share
Outstanding at December 31, 2022		12,698	$	42.92
Granted		—	$	—
Vested		—	$	—
Forfeited		6,640	$	42.92
Outstanding at December 31, 2023		6,058	$	42.92