Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Air Products Shareholders' Equity	Non-controlling Interests
Beginning balance at Sep. 30, 2021	$ 14,088.0	$ 249.4	$ 1,115.8	$ 15,678.3	$ (1,515.9)	$ (1,987.9)	$ 13,539.7	$ 548.3
Stockholders' Equity [Roll Forward]
Net income	549.6			560.4			560.4	(10.8)
Other comprehensive income (loss)	74.8				63.6		63.6	11.2
Dividends on common stock	(332.6)			(332.6)			(332.6)
Share-based compensation	14.1		14.1				14.1
Issuance of treasury shares for stock option and award plans	(19.4)		(18.1)			(1.3)	(19.4)
Investment by noncontrolling interests	3.6							3.6
Purchase of noncontrolling interests	(1.9)		0.0				0.0	(1.9)
Other equity transactions	(0.6)		0.2	(0.9)			(0.7)	0.1
Ending balance at Dec. 31, 2021	14,375.6	249.4	1,112.0	15,905.2	(1,452.3)	(1,989.2)	13,825.1	550.5
Beginning balance at Sep. 30, 2022	13,702.4	249.4	1,141.4	16,520.3	(2,786.1)	(1,981.0)	13,144.0	558.4
Stockholders' Equity [Roll Forward]
Net income	583.8			572.2			572.2	11.6
Other comprehensive income (loss)	580.5				567.8		567.8	12.7
Dividends on common stock	(359.8)			(359.8)			(359.8)
Dividends to noncontrolling interests	(0.8)							(0.8)
Share-based compensation	14.2		14.2				14.2
Issuance of treasury shares for stock option and award plans	(1.6)		(7.4)			5.8	(1.6)
Other equity transactions	(1.3)		0.2	(1.3)			(1.1)	(0.2)
Ending balance at Dec. 31, 2022	$ 14,517.4	$ 249.4	$ 1,148.4	$ 16,731.4	$ (2,218.3)	$ (1,975.2)	$ 13,935.7	$ 581.7