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Retirement Plans (Components of Accumulated Other Comprehensive Income (Loss) Related to Pension and Other Postretirement Benefits) (Details) - USD ($) $ in Millions | 12 Months Ended
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Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2013
Pension Plan, Defined Benefit [Member] |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Defined Benefit Plan, Amortization of Gains (Losses) |  | $ 3.2 | $ 3.5 | $ 9.0
Scenario, Forecast [Member] |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Defined Benefit Plan, Amortization of Prior Service Cost (Credit) | $ 0.1 |  |  |
Defined Benefit Plan, Amortization of Gains (Losses) | 3.1 |  |  |
Defined Benefit Plans, Expected Future Amortization Into Net Periodic Benefit Cost in Year One | $ 3.2 |  |  |

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- Definition The amount of gains or losses recognized in net periodic benefit cost. + 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 (h)(4) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Definition The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation. + 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 (h)(1) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Prior Service Cost -URI http://asc.fasb.org/extlink&oid=49177896 + Details
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