Employee Benefit Plans (Schedule Of Allocation Of The Fair Value Of Plan Assets) (Details)	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	100.00%
Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	100.00%	100.00%
Cash and Short-Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	5.00%
Cash and Short-Term Investments [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	20.00%	17.00%
Large Company Funds [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	33.00%	36.00%
Mid Company Funds [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	7.00%	6.00%
Small Company Funds [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	6.00%	6.00%
International Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	11.00%
International Funds [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	8.00%	10.00%
Fixed Income Funds [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	18.00%	16.00%
Growth Funds [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation percentage	8.00%	9.00%