Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Summary of Assumptions for Options Issued

The assumptions used to determine the grant date fair value for options issued during 2020, 2019, and 2018 are presented below:

	2020		2019		2018
Expected term (in years)	5.5		5.5		5.3
Volatility	25.0	%	23.6	%	23.0	%
Weighted-average risk-free interest rate	1.06	%	2.50	%	2.69	%
Dividend yield	1.39	%	1.02	%	0.74	%

Summary of Options Including Non-Plan Stock Options

A summary of option activity as of December 31, 2020, and changes during the year the ended December 31, 2020, is presented below: 

	2020
	Shares	Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (In Thousands)
Stock Options:
Outstanding at beginning of year	430,736	$	34.33	3.16	$	4,550
Plus: Granted	150,326	34.93
Less: Exercised	(115,819)	24.79
Forfeited	(15,482)	39.84
Outstanding at end of year	449,761	36.80		4.16	3,910
Nonvested at end of year	242,158	38.66		2.70	1,507
Exercisable at end of year	207,603	34.62		2.30	2,313

Schedule of Nonvested Stock Option Outstanding

The following table summarizes the non-vested stock option activity during the year the ended December 31, 2020: 

	2020
	Shares	Weighted- Average Exercise Price		Weighted- Average Grant Date Fair Value
Stock Options:
Nonvested at beginning of period	140,076	$	43.91	$	10.53
Plus: Granted	150,326	34.93		7.19
Less: Vested	(48,244)	42.32		10.27
Forfeited	—	—		—
Nonvested at end of period	242,158	38.66		8.51

Schedule of RSAs and RSUs

The following table summarizes the Company’s RSUs and changes during the year:

	Units (in whole)	Weighted Average Grant-Date Fair Value per Unit
Balance at December 31, 2019	122,660	$	44.24
Plus: Granted	154,689	37.52
Less: Vested	(64,173)	43.53
Forfeited	(3,569)	38.67
Balance at December 31, 2020	209,607	39.66