Stock Compensation Plans - Schedule of Share-based Compensation, Stock Options, Activity (Details) - $ / shares	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	245,350	436,900	614,850	77,512
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable	971,107	807,868	773,236	682,799
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 48.079	$ 49.139	$ 43.886	$ 38.860
Granted from 2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			1,000
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable			1,000	588,086
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price			$ 52.500
Exercised
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable	21,436	125,894	81,940
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 33.805	$ 33.031	$ 27.597
Forfeited from terminated plan(s)
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable	6,875	17,424
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 38.849	$ 44.163
Forfeited from current plan(s)
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	4,800	8,450	600
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable	4,800	8,450	600
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 57.513	$ 55.000	$ 55.000
Forfeited from 2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			13,773
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable			13,773
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price			$ 45.692
Termination of 2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			90,285
Available to grant from 2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			800,000
Granted from 2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	196,350	186,400	185,750
Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable	196,350	186,400	185,750
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 41.740	$ 60.086	$ 55.297

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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-Publisher FASB
-Name Accounting Standards Codification
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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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