Financial Instruments and Risk Management (Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - Recurring fair value measurement - Level 2 - USD ($) $ in Millions	Mar. 31, 2024	Sep. 30, 2023
Derivative [Line Items]
Deferred compensation liability	$ (20.5)	$ (19.4)
Derivatives - foreign currency contracts asset	2.2	5.6
Net assets (liabilities) at estimated fair value	$ (18.3)	$ (13.8)

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-SubTopic 10
-Topic 815
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480463/815-10-45-5

Name:	us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant