Stock-Based Compensation (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Weighted Average Assumptions

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions used:

Grant Year	Dividend Yield			Expected Volatility			Risk Free Interest Rate			Expected Lives
2020		5	%		45	%		2	%		6
2019		5	%		46	%		2	%		6
2018		5	%		46	%		2	%		6

Stock Option Transactions under Various Stock-Based Employee Compensation Plans

Information regarding the 1996 Plan for the year ended December 31, 2020 is as follows:

	Shares			Weighted Average Exercise Price		Weighted Average Contractual Life
Outstanding, beginning of year		608,375		$	57.97
Granted		63,500			71.91
Exercised		(61,949	)		50.66
Forfeited		—			—
Expired		(11,000	)		50.81
Outstanding, end of year		598,926			60.34		5.42
Exercisable at end of year		422,626			55.06		4.25

Summary of ESPP Share Activity

The following is a summary of 2019 ESPP share activity for the three months ended March 31, 2021:

	Shares
Available for future purchases, January 1, 2021		369,771
Additional shares reserved under 2019 ESPP		86,490
Purchases		(31,824	)
Available for future purchases, March 31, 2021		424,437

The following is a summary of 2019 ESPP share activity for the year ended December 31, 2020:

	Shares
Available for future purchases, January 1, 2020		438,434
Additional shares reserved under 2019 ESPP		86,093
Purchases		(154,756	)
Available for future purchases, December 31, 2020		369,771