Consolidated Income Statements (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Sales		$ 2,502.0	$ 2,216.3	$ 4,877.2	$ 4,471.0
Cost of sales		1,745.5	1,460.1	3,377.9	2,946.7
Facility closure		23.2	0.0	23.2	0.0
Selling and administrative		210.3	201.7	413.0	403.4
Research and development		21.1	19.2	44.6	36.9
Gain on exchange with joint venture partner		36.8	0.0	36.8	0.0
Company headquarters relocation income (expense)		0.0	33.8	0.0	33.8
Other income (expense), net		9.8	8.1	32.3	20.4
Operating Income		548.5	577.2	1,087.6	1,138.2
Equity affiliates' income		69.8	88.2	139.1	146.4
Interest expense		36.1	19.3	72.8	38.0
Other non-operating income (expense), net		16.8	7.1	35.4	16.2
Income From Continuing Operations Before Taxes		599.0	653.2	1,189.3	1,262.8
Income tax provision		121.9	148.5	235.8	269.2
Income From Continuing Operations		477.1	504.7	953.5	993.6
Income (Loss) from discontinued operations, net of tax		0.0	(14.3)	10.3	(14.3)
Net Income		477.1	490.4	963.8	979.3
Net income attributable to noncontrolling interests of continuing operations		4.0	12.6	8.7	25.9
Net Income Attributable to Air Products		473.1	477.8	955.1	953.4
Net Income Attributable to Air Products
Net income from continuing operations		473.1	492.1	944.8	967.7
Net income (loss) from discontinued operations		0.0	(14.3)	10.3	(14.3)
Net Income Attributable to Air Products		$ 473.1	$ 477.8	$ 955.1	$ 953.4
Per Share Data
Basic EPS from continuing operations (in dollars per share)	[1]	$ 2.13	$ 2.22	$ 4.26	$ 4.38
Basic EPS from discontinued operations (in dollars per share)	[1]	0	(0.06)	0.05	(0.06)
Basic EPS Attributable to Air Products (in dollars per share)	[1]	2.13	2.16	4.31	4.31
Diluted EPS from continuing operations (in dollars per share)	[1]	2.13	2.21	4.25	4.36
Diluted EPS from discontinued operations (in dollars per share)	[1]	0	(0.06)	0.05	(0.06)
Diluted EPS Attributable to Air Products (in dollars per share)	[1]	$ 2.13	$ 2.15	$ 4.29	$ 4.29
Weighted Average Common Shares (in millions)
Basic		221.6	221.2	221.6	221.0
Diluted		222.5	222.3	222.5	222.2

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