Stock Award Plans (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Compensation Cost Breakdown in Statement of Earnings

The Company has share-based compensation plans which are described below. The compensation cost that has been charged against earnings for the Company’s stock award plans and the income tax benefit recognized in the statement of earnings for stock awards were as follows (in thousands):

	Year Ended December 31,
	2023		2022		2021
Compensation cost	$	14,941	$	13,865	$	15,713
Income tax benefit	$	3,616	$	3,533	$	4,410

Stock Option Valuation Assumptions

The key input variables used in valuing the stock options granted were as follows:

	Year Ended December 31,
	2023
Dividend yield	None
Average risk-free interest rate		3.7	%
Stock price volatility		35	%
Estimated option term	7 years

Employee Plan [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Stock Option Activity

The following is a summary of the stock option activity under the employee plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		396,165		$	70.06
Exercised		(117,896	)	$	60.84
Expired		(23,024	)	$	73.66
Outstanding at December 31, 2023		255,245		$	74.00

Outstanding and Exercisable Stock Options

The following table summarizes information about the Company’s outstanding and exercisable stock options under the employee plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregated Intrinsic Value (in thousands)
$64.89		15,500		1.3	$	64.89				15,500	$	64.89
$73.29 – $75.50		233,040		2.1	$	74.29				233,040	$	74.29
$84.90		6,705		2.3	$	84.90				6,705	$	84.90
$64.89 – $84.90		255,245		2.0	$	74.00	$	1,187		255,245	$	74.00	$	1,187

RSU Activity

The following is a summary of RSU activity under the employee plan described above:

	Unvested RSUs			Weighted Average Grant Date Fair Value Per Unit
Nonvested balance at December 31, 2022		558,819		$	62.13
Granted		184,440		$	72.23
Vested		(161,550	)	$	64.85
Forfeited		(27,105	)	$	63.68
Nonvested balance at December 31, 2023		554,604		$	64.61

Director Plan [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Stock Option Activity

The following is a summary of the stock option activity under the director plan described above:

	Outstanding Non-Qualified or Nonincentive Stock Option Awards			Weighted Average Exercise Price
Outstanding at December 31, 2022		56,480		$	86.19
Granted		3,865		$	72.83
Exercised		—		$	—
Expired		(30,000	)	$	80.04
Outstanding at December 31, 2023		30,345		$	90.57

Outstanding and Exercisable Stock Options

The following table summarizes information about the Company’s outstanding and exercisable stock options under the director plan at December 31, 2023:

	Options Outstanding								Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)		Number Exercisable		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)
$70.65 – $73.57		7,053		6.6	$	71.85				6,278	$	71.75
$84.90 – $85.30		5,292		4.8	$	85.10				5,292	$	85.10
$99.52		18,000		0.3	$	99.52				18,000	$	99.52
$70.65 – $99.52		30,345		2.6	$	90.57	$	47		29,570	$	91.04	$	42

Restricted Stock Award Activity

The following is a summary of the restricted stock award activity under the director plan described above:

	Unvested Restricted Stock Award Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance at December 31, 2022		1,698		$	65.36
Granted		31,526		$	72.67
Vested		(32,604	)	$	72.29
Nonvested balance at December 31, 2023		620		$	72.65