Summarized Financial Information of Equity Affiliates (Table of Summarized Financial Information of Equity Affiliates) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Summarized Financial Information, Balance Sheet
Current assets	$ 1,556.9	$ 1,333.2
Noncurrent assets	4,340.8	4,026.9
Current liabilities	635.7	666.8
Noncurrent liabilities	2,652.5	2,194.3
Summarized Financial Information, Income Statement
Net sales	2,663.1	2,343.3	$ 2,271.6
Sales less cost of sales	1,050.6	878.6	871.5
Operating income	635.3	509.5	482.1
Net income	$ 388.0	$ 343.5	$ 334.1

Equity Method Investment, Summarized Financial Information, Balance Sheet [Abstract]

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