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Benefit Plans (Actuarial Assumptions for Benefit Obligations) (Details) | Dec. 31, 2017 | Dec. 31, 2016
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Pension Plans, Defined Benefit |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Discount rate | 3.55% | 3.95%
Expected long term rate of return | 7.50% | 7.50%
Other Postretirement Benefits Plan |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Discount rate | 2.75% | 2.75%

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- Definition Long term rate of return on asset assumption used in calculating benefit plan obligation. + 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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=82843861&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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