Pension And Other Postretirement Benefit Plans Pension And Other Postretirement Benefit Plans (Narrative) (Details) $ in Millions	6 Months Ended
Sep. 30, 2018 USD ($)
Pension and Other Postretirement Benefits [Line Items]
Contributions to qualified and non-qualified pension plans	$ 7.0
Expected additional contributions in the current fiscal year	$ 17.7

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