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Pension and Other Postretirement Benefits (Schedule of Plan Asset Mix Prior Year) (Details) | Dec. 31, 2020 | Dec. 31, 2019
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Pension Plan | Domestic Equities | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 12.00% | 12.00%
Pension Plan | Domestic Equities | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 32.00% | 32.00%
Pension Plan | International Equities | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 6.00% | 6.00%
Pension Plan | International Equities | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 16.00% | 16.00%
Pension Plan | Fixed Income | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 59.00%
Pension Plan | Fixed Income | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 71.00%
Pension Plan | Real Estate | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 0.00%
Pension Plan | Real Estate | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 7.00%
Pension Plan | Short-Term Investments | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%
Pension Plan | Short-Term Investments | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 10.00% | 10.00%
Pension Plan | Private Equity | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%
Pension Plan | Private Equity | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 5.00% | 5.00%
Other Postretirement Benefits | Domestic Equities | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%
Other Postretirement Benefits | Domestic Equities | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 55.00% | 55.00%
Other Postretirement Benefits | International Equities | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%
Other Postretirement Benefits | International Equities | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 25.00% | 25.00%
Other Postretirement Benefits | Fixed Income | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 20.00%
Other Postretirement Benefits | Fixed Income | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 100.00%
Other Postretirement Benefits | Real Estate | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 0.00%
Other Postretirement Benefits | Real Estate | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 0.00%
Other Postretirement Benefits | Short-Term Investments | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%
Other Postretirement Benefits | Short-Term Investments | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 10.00% | 10.00%
Other Postretirement Benefits | Private Equity | Minimum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%
Other Postretirement Benefits | Private Equity | Maximum |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage | 0.00% | 0.00%

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- Definition Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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