Earnings Per Share (Schedule of Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Numerator
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
Denominator (in millions)
Weighted average common shares — Basic		222.3	222.0	221.6
Employee stock option and other award plans		0.4	0.5	0.9
Weighted average common shares — Diluted		222.7	222.5	222.5
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

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