Variable Interest Entities (NGHC Joint Venture by Balance Sheet Items) (Details) - USD ($) $ in Millions		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Assets
Cash and cash items		$ 1,856.0	$ 2,979.7
Trade receivables, net		1,901.2	1,821.6
Prepaid expenses		174.9	179.9
Other receivables and current assets		689.5	610.8
Total Current Assets		5,825.8	6,363.0
Plant and equipment, net		25,337.8	23,370.9	$ 17,472.1
Operating lease right-of-use assets, net		944.0	1,047.7
Other noncurrent assets		1,021.3	1,171.5
Total Noncurrent Assets		35,233.7	33,211.6
Total Assets	[1]	41,059.5	39,574.6
Liabilities
Payables and accrued liabilities		3,237.7	2,926.2
Accrued income taxes		179.4	558.5
Short-term borrowings		34.7	83.5
Total Current Liabilities		4,218.6	4,179.6
Noncurrent operating lease liabilities		616.0	677.9
Other noncurrent liabilities		1,348.1	1,350.5
Deferred income taxes		579.6	1,159.9
Total Noncurrent Liabilities		19,491.1	16,721.3
Total Liabilities	[1]	23,709.7	20,900.9
Equity
Accumulated other comprehensive income		(2,087.8)	(2,027.7)
Noncontrolling interests	[1]	2,324.9	1,637.2
Nonrelated Party
Liabilities
Long-term debt		16,769.9	13,428.6
Variable Interest Entity, Primary Beneficiary | NEOM Green Hydrogen Company
Assets
Cash and cash items		40.3	34.5
Trade receivables, net		1.1	6.7
Prepaid expenses		20.7	31.2
Other receivables and current assets		107.2	120.6
Total Current Assets		169.3	193.0
Plant and equipment, net		6,593.9	3,929.9
Operating lease right-of-use assets, net		218.0	233.9
Other noncurrent assets		153.5	37.1
Total Noncurrent Assets		6,965.4	4,200.9
Total Assets		7,134.7	4,393.9
Liabilities
Payables and accrued liabilities		201.7	308.4
Accrued income taxes		1.2	2.0
Short-term borrowings		24.0	51.6
Total Current Liabilities		226.9	362.0
Long-term debt		4,677.6	3,053.3
Noncurrent operating lease liabilities		17.8	24.5
Other noncurrent liabilities		1.6	30.4
Deferred income taxes		13.8	3.2
Total Noncurrent Liabilities		4,710.8	3,111.4
Total Liabilities		4,937.7	3,473.4
Equity
Accumulated other comprehensive income		38.3	13.8
Noncontrolling interests		$ 1,493.6	$ 937.6

[1] Includes balances associated with a consolidated variable interest entity ("VIE"), including amounts reflected in "Total Assets" that can only be used to settle obligations of the VIE of $7,134.7 and $4,393.9 as of 30 September 2025 and 2024, respectively, as well as liabilities of the VIE reflected within "Total Liabilities" for which creditors do not have recourse to the general credit of Air Products of $4,937.7 and $3,473.4 as of 30 September 2025 and 2024, respectively. Refer to Note 3, Variable Interest Entities, for additional information regarding the NEOM Green Hydrogen Company joint venture.