Pension Plans And Other Postretirement Benefits (Narrative) (Details) $ in Thousands	9 Months Ended
Sep. 30, 2020 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions made by the Company	$ 16,277

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration