Earnings Per Share (Schedule of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income from continuing operations		$ 446.5	$ 488.0	$ 1,414.2	$ 1,256.8
Net loss from discontinued operations		0.0	0.0	(14.3)	0.0
Net Income Attributable to Air Products		$ 446.5	$ 488.0	$ 1,399.9	$ 1,256.8
Weighted average common shares — Basic		221.2	220.6	221.1	220.2
Employee stock option and other award plans		1.2	1.3	1.2	1.2
Weighted average common shares — Diluted		222.4	221.9	222.3	221.4
Basic Earnings Per Common Share Attributable to Air Products
Basic earnings per share from continuing operations (in dollars per share)	[1]	$ 2.02	$ 2.21	$ 6.40	$ 5.71
Basic earnings per share from discontinued operations (in dollars per share)	[1]	0	0	(0.06)	0
Basic Earnings Per Common Share Attributable to Air Products (in dollars per share)	[1]	2.02	2.21	6.33	5.71
Diluted Earnings Per Common Share Attributable to Air Products
Diluted earnings per share from continuing operations (in dollars per share)	[1]	2.01	2.20	6.36	5.68
Diluted earnings per share from discontinued operations (in dollars per share)	[1]	0	0	(0.06)	0
Diluted Earnings Per Common Share Attributable to Air Products (in dollars per share)	[1]	$ 2.01	$ 2.20	$ 6.30	$ 5.68

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