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Stock-Based Compensation (Textuals) (Details)	12 Months Ended
Stock-Based Compensation (Textuals) (Details)	Dec. 31, 2019 USD ($) plan shares	Dec. 31, 2018 shares	Dec. 31, 2017 shares	Dec. 31, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant/issuance	3,119,314
Unrecognized compensation expense for all nonvested awards \| $	$ 21,200,000
Weighted average period for recognition	1 year 7 months 6 days
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards, expiration period	10 years
Number of shares reduced for each award granted	1
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Awards, expiration period	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	35,993	39,819	51,368	116,087
Award Types Other than Stock Options and Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reduced for each award granted	2.5
Employee Stock Purchase Plan (ESPP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant/issuance	3,800,000
Percentage of current market price for sales to eligible employees	85.00%
Limitation on payroll deductions of employee's base salary, percent	25.00%
Limitation on payroll deductions of employee's base salary, amount \| $	$ 25,000
Maximum number of shares per employee	2,000
Maximum number of shares per employee, per year		8,000
Purchases of shares	51,391	55,669	56,218
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at target level	13,308	0
Annual Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at target level	1,300	1,500	1,800
Vesting period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	0	200	800
Cash-settled PSU awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at target level	806	560	598
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	0	0	0
Stock-settled PSU awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at target level	84,309	102,307	92,045
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	16,204	23,946	110
Deferred Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation conversion unit	1
Number of deferred compensation plans \| plan	2
Number of deferred stock units	366,159
Number of deferred stock units payable in cash	6,274
Deferred Compensation Plans [Member] \| Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at target level	14,579