Accumulated Other Comprehensive Loss (Reclassification) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales	$ (2,931.5)	$ (2,997.4)
Cost of sales	2,016.5	2,067.2
Other non-operating income (expense), net	(38.9)	14.8
Net Income attributable to Air Products	(617.4)	(609.3)
Reclassification out of Accumulated Other Comprehensive Income | Loss (Gain) on Cash Flow Hedges, net of tax
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales	0.2	0.2
Cost of sales	0.8	1.0
Interest expense	0.3	0.8
Other non-operating income (expense), net	90.6	(44.2)
Net Income attributable to Air Products	91.9	(42.2)
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefits, net of tax
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net Income attributable to Air Products	$ 11.0	$ 13.7