Note 10 - Stock Plans (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block]

	2023					2022
				Weighted-					Weighted-
	Shares			average grant		Shares			average grant
	granted			date fair value		granted			date fair value
Director plan		-		$	-		18,000	(2)	$	49.85
Omnibus plan		18,000	(2)		49.43		16,520	(3)		49.85
Omnibus plan		17,684	(3)		49.43		50	(1)		35.91
Omnibus plan		50	(1)		49.43		-
Omnibus plan		1,000	(3)		44.06		-
Total		36,734		$	49.28		34,570		$	49.83

Nonvested Restricted Stock Shares Activity [Table Text Block]

	2012 & 2022 Stock incentive plans
	Director			Omnibus			Total			Weighted- average grant date fair value
Non-vested balance at December 31, 2021		14,920			28,123			43,043		$	53.20
Granted		18,000			16,570			34,570			49.83
Forfeited		-			(3,428	)		(3,428	)		52.13
Vested		(9,048	)		(2,651	)		(11,699	)		52.83
Non-vested balance at December 31, 2022		23,872			38,614			62,486		$	51.46
Granted		-			36,734			36,734			49.28
Forfeited		-			(1,020	)		(1,020	)		50.06
Vested		(11,353	)		(13,128	)		(24,481	)		52.57
Non-vested balance at December 31, 2023		12,519			61,200			73,719		$	50.03

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

	Awards			Weighted-average grant date fair value		Weighted-average remaining contractual term (years)
Outstanding December 31, 2021		94,332		$	9.66		5.5
Granted		-
Exercised		(3,608	)		4.20
Forfeited		(3,591	)		14.41
Outstanding December 31, 2022		87,133		$	9.69		4.5
Granted		-
Exercised		(22,807	)		4.34
Forfeited		-
Outstanding December 31, 2023		64,326		$	11.59		3.8

Share-Based Payment Arrangement, Cost by Plan [Table Text Block]

(dollars in thousands)	2023		2022
Stock-based compensation expense:
2012 Director stock incentive plan	$	484	$	623
2012 Omnibus stock incentive plan		479		615
2022 Omnibus stock incentive plan		651		1
Employee stock purchase plan		34		32
Total stock-based compensation expense	$	1,648	$	1,271

Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block]

	As of
(dollars in thousands)	December 31, 2023
Unrecognized stock-based compensation expense:
2012 Director stock incentive plan	$	289
2012 Omnibus stock incentive plan		306
2022 Omnibus stock incentive plan		1,134
Total unrecognized stock-based compensation expense	$	1,729