Consolidated Income Statements - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Sales		$ 12,600.0	$ 12,698.6	$ 10,323.0
Cost of sales		8,833.0	9,338.5	7,186.1
Facility closure		0.0	0.0	23.2
Selling and administrative expense		957.0	900.6	828.4
Research and development expense		105.6	102.9	93.5
Business and asset actions		244.6	73.7	0.0
Gain on exchange with joint venture partner		0.0	0.0	36.8
Other income (expense), net		34.8	55.9	52.8
Operating Income		2,494.6	2,338.8	2,281.4
Equity affiliates' income		604.3	481.5	294.1
Interest expense		177.5	128.0	141.8
Other non-operating income (expense), net		(39.0)	62.4	73.7
Income From Continuing Operations Before Taxes		2,882.4	2,754.7	2,507.4
Income tax provision		551.2	500.8	462.8
Income From Continuing Operations		2,331.2	2,253.9	2,044.6
Income from discontinued operations, net of tax		7.4	12.6	70.3
Net Income		2,338.6	2,266.5	2,114.9
Net income attributable to noncontrolling interests of continuing operations		38.4	10.4	15.8
Net Income Attributable to Air Products		2,300.2	2,256.1	2,099.1
Net Income Attributable to Air Products
Net income from continuing operations		2,292.8	2,243.5	2,028.8
Net income from discontinued operations		7.4	12.6	70.3
Net Income Attributable to Air Products		$ 2,300.2	$ 2,256.1	$ 2,099.1
Per Share Data
Basic EPS from continuing operations	[1]	$ 10.31	$ 10.11	$ 9.16
Basic EPS from discontinued operations	[1]	0.03	0.06	0.32
Basic EPS attributable to Air Products (in dollars per share)	[1]	10.35	10.16	9.47
Diluted EPS from continuing operations	[1]	10.30	10.08	9.12
Diluted EPS from discontinued operations	[1]	0.03	0.06	0.32
Diluted EPS attributable to Air Products (in dollars per share)	[1]	$ 10.33	$ 10.14	$ 9.43
Weighted Average Common Shares (in millions)
Basic		222.3	222.0	221.6
Diluted		222.7	222.5	222.5

[1] Earnings per share ("EPS") is calculated independently for each component and may not sum to total EPS due to rounding.