Acquisitions and Divestitures (Deconsolidation) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Jan. 31, 2025	Sep. 30, 2024
Schedule of Equity Method Investments [Line Items]
Investment in net assets of and advances to equity affiliates	$ 5,366.1		$ 4,792.5
Blue Hydrogen Industrial Gases Company
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	26.00%
Derecognized plant and equipment	$ 600.0
Derecognized long-term debt, net of deferred financing costs	655.0
Investment in net assets of and advances to equity affiliates	$ 164.6
Air Products Qudra ("APQ")
Schedule of Equity Method Investments [Line Items]
Subsidiary, Ownership Percentage		51.00%
Air Products Qudra ("APQ") | Blue Hydrogen Industrial Gases Company
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%