Financial Instruments and Risk Management (Narrative) (Details) $ in Millions		12 Months Ended
		Sep. 30, 2023 USD ($) contracts	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Derivative [Line Items]
Total long-term debt, including current maturities		$ 1,372.0	$ 1,405.0
Variable rate debt
Derivative [Line Items]
Variable rate debt outstanding		122.0
Fixed rate debt
Derivative [Line Items]
Fair value of long-term debt		1,028.6	$ 945.9
Total long-term debt, including current maturities		$ 1,250.0
Customer concentration risk | Wal-Mart | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		19.00%
Sun and Skin Care | Customer concentration risk | Target | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		9.00%
Feminine Care | Customer concentration risk | Target | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		10.00%
Razors and blades | Wet Shave | Product concentration risk | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		49.00%	51.00%	52.00%
Sun care products | Sun and Skin Care | Product concentration risk | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		20.00%	19.00%	16.00%
Designated as hedging instrument | Cash flow hedging | FX contract
Derivative [Line Items]
Estimated fair value of derivatives	[1]	$ 4.4	$ 11.3
Open foreign currency contracts (in contracts) | contracts		64
Derivative, notional amount		$ 105.4
Not designated as hedging instrument | FX contract
Derivative [Line Items]
Estimated fair value of derivatives	[1]	$ 0.9	2.0
Open foreign currency contracts (in contracts) | contracts		5
Derivative, notional amount		$ 34.5
Change in estimate of fair value of foreign currency contracts		$ 3.0	$ 8.2	$ 2.3

[1] All derivative assets are presented in Other current assets or Other assets. All derivative liabilities are presented in Other current liabilities or Other liabilities.