Inventories (Schedule of Inventory) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Sep. 30, 2020
Inventory Disclosure [Abstract]
Finished goods	$ 147.7	$ 134.5
Work in process	23.3	21.3
Raw materials, supplies and other	251.9	249.0
Inventories	$ 422.9	$ 404.8

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02.6(a)(1))
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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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-Publisher FASB
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Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.

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-Name Accounting Standards Codification
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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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-Topic 210
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