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Retirement Plans And Postretirement Benefits (Net Postretirement Benefit Costs And Postretirement Projected Benefit Obligation) (Details) | 5 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2015 | Dec. 31, 2018 | Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items] |  |  |
Discount rate |  | 3.71% | 3.20%
Discount rate |  | 3.20% | 3.61%
Postretirement Benefit Obligations [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Discount rate |  | 5.57% | 5.07%
Health care cost trend on covered charges, Initial |  | 6.53% | 6.86%
Health care cost trend on covered charges, Ultimate |  | 6.05% | 6.23%
Health care cost trend on covered charges, Years to ultimate | 8 years |  | 8 years
Postretirement Benefit Costs [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Discount rate |  | 5.07% | 4.80%
Health care cost trend on covered charges, Initial |  | 6.86% | 6.80%
Health care cost trend on covered charges, Ultimate |  | 6.23% | 5.96%
Health care cost trend on covered charges, Years to ultimate |  | 7 years | 7 years

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- Definition Defined Benefit Plan Year Rate Reached Ultimate Trend Rate. + References No definition available. + Details
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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- Definition Ultimate trend rate for health care cost for defined benefit postretirement plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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