Financial Instruments (Cash Flow and Fair Value Hedges Location and Amounts Recognized) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Total Amounts Presented in the Consolidated Income Statement in which the Effects of Cash Flow and Fair Value Hedges are Recorded
Sales	$ 2,375.2	$ 2,254.7
Cost of sales	1,632.4	1,486.6
Other income (expense), net	22.5	12.3
Interest expense	36.7	18.7
Other non-operating income (expense), net	18.6	9.1
(Gain) Loss Effects of Cash Flow Hedging:
Tax effects	0.8	0.8
Net (Gain) Loss Reclassified from OCI to Income	(1.3)	(3.6)
Cash Flow Hedges | Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.1	0.1
Tax effects	0.0	0.0
Net (Gain) Loss Reclassified from OCI to Income	0.1	0.1
Cash Flow Hedges | Cost of Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	(0.1)	(0.2)
Tax effects	0.2	0.1
Net (Gain) Loss Reclassified from OCI to Income	0.1	(0.1)
Cash Flow Hedges | Other Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.0	0.0
Tax effects	0.0	0.0
Net (Gain) Loss Reclassified from OCI to Income	0.0	0.0
Cash Flow Hedges | Interest Expense
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	1.4	1.0
Tax effects	(0.5)	(0.3)
Net (Gain) Loss Reclassified from OCI to Income	0.9	0.7
Cash Flow Hedges | Other Non-Operating Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	(3.5)	(5.3)
Tax effects	1.1	1.0
Net (Gain) Loss Reclassified from OCI to Income	(2.4)	(4.3)
Cash Flow Hedges | Forward exchange contracts | Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.1	0.1
Cash Flow Hedges | Forward exchange contracts | Cost of Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	(0.1)	(0.2)
Cash Flow Hedges | Forward exchange contracts | Other Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.0	0.0
Cash Flow Hedges | Forward exchange contracts | Interest Expense
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.0	0.0
Cash Flow Hedges | Forward exchange contracts | Other Non-Operating Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	(51.6)	(23.4)
Cash Flow Hedges | Forward exchange contracts, excluded components | Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount excluded from effectiveness testing recognized in earnings based on amortization approach	0.0	0.0
Cash Flow Hedges | Forward exchange contracts, excluded components | Cost of Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount excluded from effectiveness testing recognized in earnings based on amortization approach	0.0	0.0
Cash Flow Hedges | Forward exchange contracts, excluded components | Other Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount excluded from effectiveness testing recognized in earnings based on amortization approach	0.0	0.0
Cash Flow Hedges | Forward exchange contracts, excluded components | Interest Expense
(Gain) Loss Effects of Cash Flow Hedging:
Amount excluded from effectiveness testing recognized in earnings based on amortization approach	0.0	0.0
Cash Flow Hedges | Forward exchange contracts, excluded components | Other Non-Operating Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount excluded from effectiveness testing recognized in earnings based on amortization approach	2.8	4.5
Cash Flow Hedges | Other | Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.0	0.0
Cash Flow Hedges | Other | Cost of Sales
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.0	0.0
Cash Flow Hedges | Other | Other Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	0.0	0.0
Cash Flow Hedges | Other | Interest Expense
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	1.4	1.0
Cash Flow Hedges | Other | Other Non-Operating Income (Expense), Net
(Gain) Loss Effects of Cash Flow Hedging:
Amount reclassified from OCI into income	45.3	13.6
Fair Value Hedges | Sales
(Gain) Loss Effects of Fair Value Hedging:
Total (Gain) Loss Recognized in Income	0.0	0.0
Fair Value Hedges | Cost of Sales
(Gain) Loss Effects of Fair Value Hedging:
Total (Gain) Loss Recognized in Income	0.0	0.0
Fair Value Hedges | Other Income (Expense), Net
(Gain) Loss Effects of Fair Value Hedging:
Total (Gain) Loss Recognized in Income	0.0	0.0
Fair Value Hedges | Interest Expense
(Gain) Loss Effects of Fair Value Hedging:
Total (Gain) Loss Recognized in Income	0.0	0.0
Fair Value Hedges | Other Non-Operating Income (Expense), Net
(Gain) Loss Effects of Fair Value Hedging:
Total (Gain) Loss Recognized in Income	0.0	0.0
Fair Value Hedges | Other | Sales
(Gain) Loss Effects of Fair Value Hedging:
Hedged items	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0
Fair Value Hedges | Other | Cost of Sales
(Gain) Loss Effects of Fair Value Hedging:
Hedged items	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0
Fair Value Hedges | Other | Other Income (Expense), Net
(Gain) Loss Effects of Fair Value Hedging:
Hedged items	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0
Fair Value Hedges | Other | Interest Expense
(Gain) Loss Effects of Fair Value Hedging:
Hedged items	(1.3)	(0.9)
Derivatives designated as hedging instruments	1.3	0.9
Fair Value Hedges | Other | Other Non-Operating Income (Expense), Net
(Gain) Loss Effects of Fair Value Hedging:
Hedged items	0.0	0.0
Derivatives designated as hedging instruments	$ 0.0	$ 0.0