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Retirement Plans (Accumulated and Projected Benefit Obligations) (Details) - USD ($) $ in Millions | Sep. 30, 2017 | Sep. 30, 2016
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Pension Plans with accumulated benefit obligations in excess of plan assets |  |
Projected benefit obligation | $ 379.5 | $ 402.0
Accumulated benefit obligation | 379.5 | 402.0
Fair value of plan assets | 364.2 | 337.9
Pension plans with plan assets in excess of accumulated benefit obligations |  |
Projected benefit obligation | 1.0 | 1.1
Accumulated benefit obligation | 1.0 | 1.1
Fair value of plan assets | $ 2.1 | $ 2.1

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- Definition Defined Benefit Plan, Pension Plans with Plan Assets in Excess of Accumulated Benefit Obligations [Abstract] + References No definition available. + Details
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- Definition Defined Benefit Plan, Pension Plans With Plan Assets In Excess Of Accumulated Benefit Obligations, Aggregate Fair Value of Plan Assets + References No definition available. + Details
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- Definition Defined Benefit Plan, Pension Plans With Plan Assets In Excess Of Accumulated Benefit Obligations, Aggregate Projected Benefit Obligation + References No definition available. + Details
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- Definition Amount of accumulated benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2417-114920 + Details
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- Definition Fair value of plan assets for defined benefit pension plan with accumulated benefit obligation in excess of plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2417-114920 + Details
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