Stock Option Plans (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Activity

	2019			2018
Options outstanding at the beginning of the year		1,434,280			1,289,080
Options granted		120,000			232,200
Options forfeited		(26,500	)		(11,500	)
Options exercised		(164,086	)		(75,500	)
Options outstanding at the end of the year		1,363,694			1,434,280
Options exercisable at the end of the year		932,094			918,405
Common stock available for future grants at the end of the year		44,875			85,000
Weighted average exercise price per share:
Granted	$	19.88		$	22.75
Forfeited		23.29			23.07
Exercised		10.54			11.47
Outstanding		19.08			18.07
Exercisable		17.50			15.15

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
$7.30 to $10.74		156,969	2	$	10.17		156,969	$	10.17
$10.75 to $16.82		242,750	3		13.57		242,750		13.57
$16.83 to $22.08		448,250	7		19.52		302,625		19.23
$22.09 to $23.97		217,700	9		22.79		69,425		22.76
$23.98 to $28.20		298,025	8		24.87		160,325		25.07
		1,363,694					932,094

Assumptions Used to Value Option Grants

	2019	2018
Expected life in years	5 - 6	5
Interest rate	1.52 - 2.39%	2.43 - 3.02%
Volatility	.358 - .375	.287 - .316
Dividend yield	2.0 - 2.2%	1.8 - 2.75%