Variable Interest Entities - NGHC Joint Venture By Balance Sheet Items (Details) - USD ($) $ in Millions		Jun. 30, 2024	Sep. 30, 2023
Variable Interest Entity [Line Items]
Cash and cash items		$ 2,375.7	$ 1,617.0
Trade receivables, net		1,712.2	1,700.4
Prepaid expenses		170.7	177.0
Other receivables and current assets		601.4	722.1
Total Current Assets		5,677.4	5,200.5
Plant and equipment, net		21,482.1	17,472.1
Operating lease right-of-use assets, net		982.1	974.0
Other noncurrent assets		1,278.0	1,229.9
Total noncurrent assets		31,296.9	26,802.0
Total assets	[1]	36,974.3	32,002.5
Payables and accrued liabilities		3,168.6	2,890.1
Accrued income taxes		155.9	131.2
Short-term borrowings		159.1	259.5
Total Current Liabilities		4,474.5	3,895.8
Noncurrent operating lease liabilities		639.3	631.1
Other noncurrent liabilities		1,108.7	1,118.0
Deferred income taxes		1,182.1	1,266.0
Total noncurrent liabilities		15,812.8	12,446.4
Total Liabilities	[1]	20,287.3	16,342.2
Accumulated other comprehensive income		(2,391.1)	(2,449.4)
Noncontrolling interests	[1]	1,585.7	1,347.4
Variable Interest Entity, Primary Beneficiary | NEOM Green Hydrogen Company
Variable Interest Entity [Line Items]
Cash and cash items		233.6	78.2
Trade receivables, net		0.4	0.0
Prepaid expenses		30.6	21.4
Other receivables and current assets		82.7	181.6
Total Current Assets		347.3	281.2
Plant and equipment, net		3,123.9	1,396.1
Operating lease right-of-use assets, net		225.8	228.9
Other noncurrent assets		219.8	350.6
Total noncurrent assets		3,569.5	1,975.6
Total assets		3,916.8	2,256.8
Payables and accrued liabilities		530.6	141.0
Accrued income taxes		1.3	0.6
Short-term borrowings		149.4	0.0
Total Current Liabilities		681.3	141.6
Long-term debt		2,552.3	1,274.4
Noncurrent operating lease liabilities		18.9	18.9
Other noncurrent liabilities		24.3	2.1
Deferred income taxes		17.0	24.1
Total noncurrent liabilities		2,612.5	1,319.5
Total Liabilities		3,293.8	1,461.1
Accumulated other comprehensive income		54.8	77.7
Noncontrolling interests		$ 911.6	$ 723.6

[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 $3,916.8 and $2,256.8 as of 30 June 2024 and 30 September 2023, 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 $3,293.8 and $1,461.1 as of 30 June 2024 and 30 September 2023, respectively. Refer to Note 3, Variable Interest Entities, for additional information regarding the NEOM Green Hydrogen Company joint venture.