Stock Option Plans (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Activity

	2021			2020
Options outstanding at the beginning of the year		1,487,925			1,363,694
Options granted		299,750			280,750
Options forfeited		(5,525	)		(9,125	)
Options exercised		(245,098	)		(147,394	)
Options outstanding at the end of the year		1,537,052			1,487,925
Options exercisable at the end of the year		971,568			985,475
Common stock available for future grants at the end of the year		18,650			104,372
Weighted average exercise price per share:
Granted	$	38.38		$	23.05
Forfeited		23.01			21.72
Exercised		15.15			14.51
Outstanding		24.60			20.26
Exercisable		21.33			18.99

Summary of Options Outstanding

Options Outstanding						Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted- Average Remaining Contractual Life (Years)	Weighted- Average Exercise Price		Number Exercisable		Weighted- Average Exercise Price
$9.26 to $16.08		133,477	2	$	13.59		133,477	$	13.59
$16.09 to $21.35		250,250	5		18.40		199,250		18.09
$21.36 to $24.86		692,575	7		22.85		452,841		22.72
$24.87 to $31.56		161,000	6		25.30		161,000		25.30
$31.57 to $39.56		299,750	9		38.38		25,000		37.92
		1,537,052					971,568

Assumptions Used to Value Option Grants

	2021	2020
Expected life in years	6 - 7	6
Interest rate	.42 - 1.11%	.30 - 1.63%
Volatility	.397 - .415	.358 - .375
Dividend yield	1.3 - 1.8%	2.0 - 2.2%