Pension And Postretirement Benefits (Schedule Of Fair Value Of Company Pension Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	$ 1,024.1	$ 965.8
Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	398.7	373.9
Significant Other Observable Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	14.3	15.2
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	22.8	22.6
Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	588.3	554.1
Cash and Money Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	30.1	14.7
Cash and Money Markets [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	30.1	14.7
Common Stocks Actively Managed U.S. Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	103.2	130.6
Common Stocks Actively Managed U.S. Equities [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	103.2	130.6
Fixed Income Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	0.1	0.1
Fixed Income Investments [Member] | Significant Other Observable Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	0.1	0.1
U.S. Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	117.3	77.9
U.S. Equity Funds [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	117.3	77.9
Non-U.S. Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	231.2	203.4
Non-U.S. Equity Funds [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	53.2	44.8
Non-U.S. Equity Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	178.0	158.6
U.S. Fixed Income, Government and Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	76.6	75.7
U.S. Fixed Income, Government and Corporate [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	76.6	75.7
Non-U.S. Fixed Income, Government And Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	186.5	176.1
Non-U.S. Fixed Income, Government And Corporate [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	186.5	176.1
International Balanced Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	1.9	1.8
International Balanced Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	1.9	1.8
CollectiveTrust [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	42.0	43.8
CollectiveTrust [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	22.8	22.6
CollectiveTrust [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	19.2	21.2
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	153.8	147.3
Hedge Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	153.8	147.3
International Property Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	48.9	49.1
International Property Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	48.9	49.1
Annuity Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	14.2	15.1
Annuity Contract [Member] | Significant Other Observable Inputs Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	14.2	15.1
us-gaap-RegisteredInvestmentCompanyMember
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	18.3	30.2
us-gaap-RegisteredInvestmentCompanyMember | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value	$ 18.3	$ 30.2