Stock-Based Compensation (Details 1) - Employee Stock Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Summary of the status of the stock option plan and changes
Shares Outstanding at beginning of year	541,414	648,311	662,841
Shares Granted	101,700	101,350	94,700
Shares Exercised	(93,870)	(191,497)	(105,630)
Shares Forfeited or expired	(54,049)	(16,750)	(3,600)
Shares Outstanding at end of year	495,195	541,414	648,311
Shares options exercisable at year-end	287,548	305,991	404,851
Shares available for grant	136,339	183,990	270,090
Weighted average exercise price Outstanding at beginning of year	$ 26.65	$ 20.74	$ 15.70
Weighted average exercise price Granted	37.77	32.81	43.13
Weighted average exercise price Exercised	14.79	9.24	8.51
Weighted average exercise price Forfeited or expired	38.15	34.01	40.03
Weighted average exercise price Outstanding at end of year	29.93	26.65	20.74
Weighted average exercise price, Options exercisable at year-end	24.93	20.00	12.58
Weighted average fair value of options granted during the year	$ 11.37	$ 11.81	$ 16.76
Weighted Average Remaining Contractual Life, Outstanding at end of year	6 years 4 months 24 days	6 years 3 months 18 days	5 years 7 months 6 days
Weighted Average Remaining Contractual Life, Options exercisable at year-end	5 years	4 years 10 months 24 days	4 years