Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Disaggregation of Revenue [Line Items]
Sales	$ 3,102.5	$ 2,931.5
Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 3,102.5	$ 2,931.5
Percent sales by supply mode	100.00%	100.00%
Americas \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,341.7	$ 1,287.6
Asia \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	831.5	817.1
Europe \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	782.0	697.2
Middle East and India \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	30.3	32.8
Corporate and other \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	117.0	96.8
On-site \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,633.9	$ 1,488.3
Percent sales by supply mode	53.00%	51.00%
On-site \| Americas \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 783.9	$ 713.1
On-site \| Asia \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	569.7	529.3
On-site \| Europe \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	264.0	228.3
On-site \| Middle East and India \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	16.3	17.6
On-site \| Corporate and other \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0
Merchant \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 1,351.6	$ 1,346.4
Percent sales by supply mode	43.00%	46.00%
Merchant \| Americas \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 557.8	$ 574.5
Merchant \| Asia \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	261.8	287.8
Merchant \| Europe \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	518.0	468.9
Merchant \| Middle East and India \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	14.0	15.2
Merchant \| Corporate and other \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0
Sale of Equipment \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 117.0	$ 96.8
Percent sales by supply mode	4.00%	3.00%
Sale of Equipment \| Americas \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 0.0	$ 0.0
Sale of Equipment \| Asia \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0
Sale of Equipment \| Europe \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0
Sale of Equipment \| Middle East and India \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	0.0	0.0
Sale of Equipment \| Corporate and other \| Operating Segments
Disaggregation of Revenue [Line Items]
Sales	$ 117.0	$ 96.8
Financing And Lease Arrangment \| Revenue Benchmark \| Revenue Source Concentration Risk
Disaggregation of Revenue [Line Items]
Interest income associated with financing and lease arrangements as a percentage of total consolidated sales	1.00%	1.00%

Air Products & Chemicals, Inc. 10-Q