Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Fair Value Assumptions for Stock Options

The following are the weighted-average assumptions used to calculate the grant-date fair values of stock option awards granted in the years ended December 31, 2021, 2020 and 2019:

	For the Years Ended December 31
	2021	2020	2019
Expected dividend yield	1.30%	1.31%	1.32%
Expected volatility	31.81%	26.00%	26.98%
Expected term	7.3 years	7.3 years	7.3 years
Risk-free interest rate	0.96%	1.47%	2.53%

Summary of Stock Option Activity

A summary of stock option activity for the year ended December 31, 2021 is presented below:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value ($000)
Options
Outstanding at January 1, 2021		392,550		$	74.24
Granted		66,352			123.70
Exercised		(20,435	)		66.95
Forfeited		(2,501	)		107.86
Outstanding at December 31, 2021		435,966			81.92		6.18	$	18,474
Vested or expected to vest at December 31, 2021		429,507			81.42		6.14		18,415
Exercisable at December 31, 2021		363,297			75.34		5.67		17,783

Summary of Stock Award Activity

A summary of stock award activity for the year ended December 31, 2021, is presented below:

	Shares			Weighted-Average Grant Date Fair Value
Stock Awards
Unvested at January 1, 2021		107,351		$	94.66
Granted		40,127			119.76
Vested		(48,613	)		88.93
Forfeited/Modified due to change of assumptions		4,413			82.30
Unvested at December 31, 2021		103,278			61.30

Summary of SARs Activity

The following is a summary of SARs activity for the year ended December 31, 2021:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value ($000)
SARs
Outstanding at January 1, 2021		653,498		$	80.64
Granted		143,104			123.68
Exercised		(62,118	)		65.97
Forfeited		(7,497	)		107.86
Outstanding at December 31, 2021		726,987			90.06		6.83	$	24,885