Earnings Per Share (Schedule of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income from continuing operations		$ 530.5	$ 473.1	$ 1,090.9	$ 944.8
Net income from discontinued operations		0.0	0.0	0.0	10.3
Net Income Attributable to Air Products		$ 530.5	$ 473.1	$ 1,090.9	$ 955.1
Weighted average common shares — Basic		222.0	221.6	222.0	221.6
Employee stock option and other award plans		0.5	0.9	0.5	0.9
Weighted average common shares — Diluted		222.5	222.5	222.5	222.5
Per Share Data
Basic EPS from continuing operations (in dollars per share)	[1]	$ 2.39	$ 2.13	$ 4.91	$ 4.26
Basic EPS from discontinued operations (in dollars per share)	[1]	0	0	0	0.05
Basic EPS Attributable to Air Products (in dollars per share)	[1]	2.39	2.13	4.91	4.31
Diluted EPS from continuing operations (in dollars per share)	[1]	2.38	2.13	4.90	4.25
Diluted EPS from discontinued operations (in dollars per share)	[1]	0	0	0	0.05
Diluted EPS Attributable to Air Products (in dollars per share)	[1]	$ 2.38	$ 2.13	$ 4.90	$ 4.29

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