Pension and Postretirement Benefits Other Than Pension Plans - Pension Plans - Pension Plan Liability Re-measurement (Details) $ in Millions	9 Months Ended
Sep. 30, 2018 USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease in pension plan liability	$ 3.4

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.

No definition available.

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