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Pension and Other Postretirement Benefits (Schedule Of Fair Value Of Pension Plan Assets) (Details) - USD ($) $ in Millions | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
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Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | $ 480.4 |
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 432.0 |  |
Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1,032.3 | 934.4 |
Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Fair Value, Inputs, Level 1, 2 and 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 2,275.4 | 2,404.1 |
Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 1,975.5 | 2,110.7 |
Pension Plan | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items |  | 231.1 |
Pension Plan | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 177.3 |  |
Pension Plan | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 1,033.8 | 936.0 |
Pension Plan | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 0.0 | 0.0 |
Pension Plan | Fair Value, Inputs, Level 1, 2 and 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1,981.7 | 2,117.7 | $ 2,080.9
Pension Plan | Cash [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 10.3 | 11.9 |
Pension Plan | Cash [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 11.9 |
Pension Plan | Cash [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 9.7 |  |
Pension Plan | Cash [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.6 | 0.0 |
Pension Plan | Cash [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 150.9 | 230.1 |
Pension Plan | Fixed Income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1,382.3 | 1,291.2 |
Pension Plan | Equity Securities [Member] | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.5 |  |
Pension Plan | Equity Securities [Member] | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.5 |  |
Pension Plan | Equity Securities [Member] | International Equities | Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Equity Securities [Member] | International Equities | Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Equity Securities [Member] | United States Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 2.4 |
Pension Plan | Equity Securities [Member] | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 2.4 |
Pension Plan | Equity Securities [Member] | United States Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Equity Securities [Member] | United States Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Fixed Income Securities [Member] | Government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 387.3 | 243.4 |
Pension Plan | Fixed Income Securities [Member] | Government | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Fixed Income Securities [Member] | Government | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Fixed Income Securities [Member] | Government | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 387.3 | 243.4 |
Pension Plan | Fixed Income Securities [Member] | Government | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Fixed Income Securities [Member] | Corporate/Other debt securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 645.9 | 692.6 |
Pension Plan | Fixed Income Securities [Member] | Corporate/Other debt securities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Fixed Income Securities [Member] | Corporate/Other debt securities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Fixed Income Securities [Member] | Corporate/Other debt securities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 645.9 | 692.6 |
Pension Plan | Fixed Income Securities [Member] | Corporate/Other debt securities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 111.7 | 176.8 |
Pension Plan | Commingled Funds | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Commingled Funds | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Commingled Funds | International Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | International Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | Fixed Income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 349.1 | 337.6 |
Pension Plan | Commingled Funds | Fixed Income | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Commingled Funds | Fixed Income | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Commingled Funds | Fixed Income | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | Fixed Income | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | United States Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 195.9 | 279.7 |
Pension Plan | Commingled Funds | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Commingled Funds | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Commingled Funds | United States Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | United States Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | Short-Term Money Markets |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 55.0 | 78.8 |
Pension Plan | Commingled Funds | Short-Term Money Markets | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Commingled Funds | Short-Term Money Markets | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Commingled Funds | Short-Term Money Markets | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Commingled Funds | Short-Term Money Markets | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | U.S. Multi-Strategy [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 10.9 | 10.9 |
Pension Plan | Private Equity Limited Partnerships [Member] | U.S. Multi-Strategy [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | U.S. Multi-Strategy [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Private Equity Limited Partnerships [Member] | U.S. Multi-Strategy [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | U.S. Multi-Strategy [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | International Multi-Strategy [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 4.5 | 6.6 |
Pension Plan | Private Equity Limited Partnerships [Member] | International Multi-Strategy [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | International Multi-Strategy [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Private Equity Limited Partnerships [Member] | International Multi-Strategy [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | International Multi-Strategy [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | Distressed Opportunities [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.1 | 0.3 |
Pension Plan | Private Equity Limited Partnerships [Member] | Distressed Opportunities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | Distressed Opportunities [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Private Equity Limited Partnerships [Member] | Distressed Opportunities [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Private Equity Limited Partnerships [Member] | Distressed Opportunities [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Real Estate [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 37.2 | 52.9 |
Pension Plan | Real Estate [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Real Estate [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Pension Plan | Real Estate [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Real Estate [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Mutual Funds [Member] | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 38.7 | 55.4 |
Pension Plan | Mutual Funds [Member] | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 55.4 |
Pension Plan | Mutual Funds [Member] | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 38.7 |  |
Pension Plan | Mutual Funds [Member] | International Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Mutual Funds [Member] | International Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Mutual Funds [Member] | U.S. Multi-Strategy [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 128.4 | 161.3 |
Pension Plan | Mutual Funds [Member] | U.S. Multi-Strategy [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 161.3 |
Pension Plan | Mutual Funds [Member] | U.S. Multi-Strategy [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 128.4 |  |
Pension Plan | Mutual Funds [Member] | U.S. Multi-Strategy [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Mutual Funds [Member] | U.S. Multi-Strategy [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Pension Plan | Mutual Funds [Member] | Fixed Income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.1 |
Pension Plan | Mutual Funds [Member] | Fixed Income | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.1 |
Pension Plan | Mutual Funds [Member] | Fixed Income | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Pension Plan | Mutual Funds [Member] | Fixed Income | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 293.4 | 286.4 |
Other Postretirement Benefits | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items |  | 240.7 |
Other Postretirement Benefits | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 246.7 |  |
Other Postretirement Benefits | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 0.0 | 0.0 |
Other Postretirement Benefits | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Fair Value Of Plan Assets Before Pending Items | 0.0 | 0.0 |
Other Postretirement Benefits | Fair Value, Inputs, Level 1, 2 and 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 293.7 | 286.4 | $ 261.4
Other Postretirement Benefits | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 50.5 | 48.2 |
Other Postretirement Benefits | Fixed Income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 118.8 | 122.0 |
Other Postretirement Benefits | Due To Brokers Net [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | (1.8) | (1.6) |
Other Postretirement Benefits | Due To Brokers Net [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Other Postretirement Benefits | Due To Brokers Net [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Other Postretirement Benefits | Due To Brokers Net [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | (1.8) | (1.6) |
Other Postretirement Benefits | Due To Brokers Net [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Accrued Investment Income Dividends [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 8.0 | 8.6 |
Other Postretirement Benefits | Accrued Investment Income Dividends [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 8.6 |
Other Postretirement Benefits | Accrued Investment Income Dividends [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 8.0 |  |
Other Postretirement Benefits | Accrued Investment Income Dividends [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Accrued Investment Income Dividends [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Receivables/Payables |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.3 |  |
Other Postretirement Benefits | Receivables/Payables | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Other Postretirement Benefits | Receivables/Payables | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.3 |  |
Other Postretirement Benefits | Receivables/Payables | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Other Postretirement Benefits | Commingled Funds | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 26.1 | 24.1 |
Other Postretirement Benefits | Commingled Funds | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Other Postretirement Benefits | Commingled Funds | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Other Postretirement Benefits | Commingled Funds | International Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Commingled Funds | International Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Commingled Funds | United States Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 14.8 | 14.0 |
Other Postretirement Benefits | Commingled Funds | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Other Postretirement Benefits | Commingled Funds | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Other Postretirement Benefits | Commingled Funds | United States Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Commingled Funds | United States Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Commingled Funds | Short-Term Money Markets |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 5.8 | 7.6 |
Other Postretirement Benefits | Commingled Funds | Short-Term Money Markets | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 0.0 |
Other Postretirement Benefits | Commingled Funds | Short-Term Money Markets | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 |  |
Other Postretirement Benefits | Commingled Funds | Short-Term Money Markets | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Commingled Funds | Short-Term Money Markets | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Mutual Funds [Member] | International Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 24.4 | 24.1 |
Other Postretirement Benefits | Mutual Funds [Member] | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 24.1 |
Other Postretirement Benefits | Mutual Funds [Member] | International Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 24.4 |  |
Other Postretirement Benefits | Mutual Funds [Member] | International Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Mutual Funds [Member] | International Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Mutual Funds [Member] | Fixed Income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 118.5 | 121.8 |
Other Postretirement Benefits | Mutual Funds [Member] | Fixed Income | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 121.8 |
Other Postretirement Benefits | Mutual Funds [Member] | Fixed Income | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 118.5 |  |
Other Postretirement Benefits | Mutual Funds [Member] | Fixed Income | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Mutual Funds [Member] | Fixed Income | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Mutual Funds [Member] | United States Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 103.8 | 94.8 |
Other Postretirement Benefits | Mutual Funds [Member] | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount |  | 94.8 |
Other Postretirement Benefits | Mutual Funds [Member] | United States Equities | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fair Value, Recurring |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 103.8 |  |
Other Postretirement Benefits | Mutual Funds [Member] | United States Equities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Other Postretirement Benefits | Mutual Funds [Member] | United States Equities | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 0.0 | 0.0 |
Underfunded Plan [Member] | Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | 1,981.7 | 2,117.7 |
Underfunded Plan [Member] | Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Amount | $ 0.0 | $ 0.0 |

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