Acquisition - Pro Forma Information and Significant Adjustments (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Business Combinations [Abstract]
Pro forma net sales	$ 578.5	$ 607.5	$ 1,353.2	$ 1,393.2
Pro forma net earnings/(loss) from continuing operations	16.1	15.2	103.2	(25.1)
Pro forma mandatory preferred stock dividends	4.1	4.1	8.1	8.1
Pro forma net earnings/(loss) from continuing operations attributable to common shareholders	$ 12.0	$ 11.1	$ 95.1	$ (33.2)
Pro forma diluted net earnings/(loss) per common share - continuing operations (in usd per share)	$ 0.17	$ 0.16	$ 1.34	$ (0.47)
Pro forma weighted average shares of common stock - Diluted (in shares)	71.0	71.1	71.0	71.3
Inventory step up	$ 22.5	$ 0.0	$ 22.0	$ (26.5)
Acquisition and integration costs	30.1	16.7	50.3	(48.9)
Interest and ticking fees on escrowed debt	27.5	2.8	53.0	2.2
Gains on escrowed funds	0.0	$ 0.0	(12.0)	$ 0.0
Interest, pre-tax	$ 47.6		$ 95.2

Acquisition and Integration Costs

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- Definition

Business Acquisition, Preferred Stock Dividends and Other Adjustments

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- Definition

Gain on Escrowed Funds

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Interest and Ticking Fees on Escrowed Debt

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Interest on Escrowed Debt, Pre-tax Amount

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- Definition

Per diluted share amount of pro forma income from continuing operations, after tax, as if the business combination had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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- Definition

Amount after tax of pro forma income from continuing operations as if the business combination had been completed at the beginning of a period.

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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to inventory acquired in connection with a business combination for which the initial accounting was incomplete.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 4A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84161108&loc=SL65897772-128472

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The weighted average number of shares or units and dilutive common stock or unit equivalents outstanding in the calculation of proforma diluted earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

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