Financial Instruments and Risk Management (Narrative) (Details) $ in Millions		12 Months Ended
		Sep. 30, 2024 USD ($) contracts	Sep. 30, 2023 USD ($)	Sep. 30, 2022
Derivative [Line Items]
Total long-term debt, including current maturities		$ 1,284.0	$ 1,372.0
Variable rate debt
Derivative [Line Items]
Variable rate debt outstanding		34.0
Fixed rate debt
Derivative [Line Items]
Fair value of long-term debt		1,180.0	$ 1,028.6
Total long-term debt, including current maturities		$ 1,250.0
Customer concentration risk | Wal-Mart | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		17.20%
Sun and Skin Care | Customer concentration risk | Target | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		9.50%
Feminine Care | Customer concentration risk | Target | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		9.80%
Razors and blades | Wet Shave | Product concentration risk | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		49.30%	49.00%	51.10%
Sun care products | Sun and Skin Care | Product concentration risk | Percentage of Revenue
Derivative [Line Items]
Concentration risk, percentage		21.50%	20.00%	18.50%
Designated as hedging instrument | Cash flow hedging | FX contract
Derivative [Line Items]
Estimated fair value of derivatives	[1]	$ (2.4)	$ 4.4
Open foreign currency contracts (in contracts) | contracts		64
Derivative, notional amount		$ 106.5
Not designated as hedging instrument | FX contract
Derivative [Line Items]
Estimated fair value of derivatives	[1]	$ 0.1	$ 0.9
Open foreign currency contracts (in contracts) | contracts		1
Derivative, notional amount		$ 9.0
Change in estimate of fair value of foreign currency contracts		$ 0.4

[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.