Note 17 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Schedule of Share-based Compensation Arrangement by Share-based Payment Award Fair Value Assumptions and Methodology [Table Text Block]

	2020			2019			2018
Dividend yield		2.51	%		2.54	%		2.56	%
Expected volatility		20.87	%		20.39	%		20.17	%
Risk free interest rate		1.25	%		2.52	%		2.96	%
Expected life of SARs (years)		7.1			7.2			7.0

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year Ended December 31, 2020
(in thousands)	Stock Appreciation Rights			Restricted Stock Awards			Restricted Stock Units			Performance Stock Units			Total
Expense	$	352		$	1,346		$	270		$	1,294		$	3,262
Deferred tax benefit		(74	)		(283	)		(57	)		(272	)		(686	)
Total net expense	$	278		$	1,063		$	213		$	1,022		$	2,576

	Year Ended December 31, 2019
(in thousands)	Stock Appreciation Rights			Restricted Stock Awards			Restricted Stock Units			Performance Stock Units			Total
Expense	$	345		$	1,185		$	329		$	1,719		$	3,578
Deferred tax benefit		(72	)		(249	)		(69	)		(361	)		(751	)
Total net expense	$	273		$	936		$	260		$	1,358		$	2,827

	Year Ended December 31, 2018
(in thousands)	Stock Appreciation Rights			Restricted Stock Awards			Restricted Stock Units			Performance Stock Units			Total
Expense	$	379		$	1,100		$	248		$	2,300		$	4,027
Deferred tax benefit		(80	)		(231	)		(52	)		(483	)		(846	)
Total net expense	$	299		$	869		$	196		$	1,817		$	3,181

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

(in thousands) Year Ended	Stock Appreciation Rights		Restricted Stock Awards		Restricted Stock Units		Performance Stock Units		Total
2021	$	304	$	994	$	1	$	760	$	2,059
2022		249		762		—		490		1,501
2023		174		546		—		—		720
2024		68		292		—		—		360
2025		9		28		—		—		37
Total estimated expense	$	804	$	2,622	$	1	$	1,250	$	4,677

Share-based Payment Arrangement, Option and Stock Appreciation Rights, Activity [Table Text Block]

(dollars in thousands, except per share and years)	SARs			Exercise price			Weighted average exercise price		Aggregate intrinsic value(1)		Weighted average fair value		Weighted average remaining contractual life (in years)
Outstanding, January 1, 2018		704		$14.02	-	40.00	$	19.51	$	12,923	$	3.47		5.1
Granted		100		35.90	-	39.32		37.75		—		6.07
Exercised		(73	)	14.02	-	19.37		15.32		1,654		3.43
Forfeited		—			—			—		—		—
Outstanding, December 31, 2018		731		$14.02	-	40.00	$	22.42	$	8,422	$	3.83		5.2
Outstanding, January 1, 2019		731		$14.02	-	40.00	$	22.42	$	8,422	$	3.83		5.2
Granted		53		36.65	-	38.18		37.01		213		6.24
Exercised		(143	)	14.02	-	22.96		15.99		3,025		3.47
Forfeited		—			—			—		—		—
Outstanding, December 31, 2019		641		$14.02	-	40.00	$	25.06	$	10,250	$	4.10		5.3
Outstanding, January 1, 2020		641		$14.02	-	40.00	$	25.06	$	10,250	$	4.10		5.3
Granted		48		37.30	-	37.30		37.30		154		5.80
Exercised		(96	)	14.02	-	25.76		16.33		2,401		2.88
Forfeited		—			—			—		—		—
Outstanding, December 31, 2020		593		$15.24	-	40.00	$	27.47	$	7,706	$	4.44		5.1
Vested and exercisable		412		$15.24	-	40.00	$	23.44	$	7,008	$	3.83		4.0
Unvested		181		25.76	-	40.00		36.63		698		5.83		7.8
Outstanding, December 31, 2020		593		$15.24	-	40.00	$	27.47	$	7,706	$	4.44		5.1
Vested in the current year		68		$22.96	-	40.00	$	32.11	$	572	$	5.10

Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights, Award Expiration Period [Table Text Block]

(in thousands, except per share data)
Expiration	SARs Outstanding		SARs Exercisable		Weighted Average Exercise Price
2021		8		8		15.84
2022		42		42		15.26
2023		80		80		15.26
2024		73		73		19.37
2025		63		63		23.00
2026		79		63		25.84
2027		46		29		40.00
2028		100		42		37.75
2029		53		12		37.01
2030		49		—		37.30
		593		412	$	27.47

Schedule of Nonvested Share Activity [Table Text Block]

				Weighted
				average cost
(in thousands, except per share data)	RSAs			at grant date
Unvested at January 1, 2018		119		$	27.62
Shares awarded		40			35.89
Restrictions lapsed and shares vested		(44	)		23.62
Shares forfeited		(5	)		31.35
Unvested at December 31, 2018		110		$	32.09
Unvested at January 1, 2019		110		$	32.09
Shares awarded		40			34.88
Restrictions lapsed and shares vested		(40	)		28.74
Shares forfeited		(2	)		35.36
Unvested at December 31, 2019		108		$	34.31
Unvested at January 1, 2020		108		$	34.31
Shares awarded		36			39.30
Restrictions lapsed and shares vested		(41	)		32.38
Shares forfeited		(4	)		36.63
Unvested at December 31, 2020		99		$	36.85

Share-based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]

Grant Year	Vesting Period in Years	Fair Value		Expected Shares to be Awarded
2018	3		31.54		50,352
2019	3		32.03		36,127
2020	3		32.27		45,577

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares to be Issued Upon Exercise and Remaining Shares Available for Future Issuance [Table Text Block]

	Number of				Shares
	shares to be		Weighted		available for
	issued upon		average		future
Plan category (in thousands)	exercising/vesting		exercise price		issuance (a)
Equity compensation plans approved by security holders:
Stock Appreciation Rights	(b)		(b)			432
Restricted Stock Awards		99		N/A	(a)
Restricted Stock Units		7		N/A	(a)
Performance Stock Units	(c)			N/A	(a)
Total shares		106				432