Consolidated Income Statements (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Sales	$ 1,980.1	$ 1,777.4	$ 3,862.6	$ 3,643.7
Cost of sales	1,403.8	1,213.0	2,721.9	2,508.9
Selling and administrative	177.9	167.8	343.6	341.7
Research and development	14.8	18.2	29.9	35.1
Business separation costs	0.0	7.4	30.2	19.4
Cost reduction and asset actions	10.3	10.7	60.3	10.7
Pension settlement loss	4.1	2.0	4.1	2.0
Other income (expense), net	22.0	13.3	46.7	18.2
Operating Income	391.2	371.6	719.3	744.1
Equity affiliates’ income	34.2	32.3	72.2	65.6
Interest expense	30.5	25.7	60.0	47.9
Other non-operating income (expense), net	9.7	0.0	9.7	0.0
Income From Continuing Operations Before Taxes	404.6	378.2	741.2	761.8
Income tax provision	94.5	93.5	172.9	189.9
Income from Continuing Operations	310.1	284.7	568.3	571.9
Income (Loss) From Discontinued Operations, net of tax	1,825.6	(750.2)	1,873.8	(665.4)
Net Income (Loss)	2,135.7	(465.5)	2,442.1	(93.5)
Net Income Attributable to Noncontrolling Interests of Continuing Operations	5.7	5.8	12.3	12.1
Net Income Attributable to Noncontrolling Interests of Discontinued Operations	0.0	2.0	0.0	4.1
Net Income (Loss) Attributable to Air Products	2,130.0	(473.3)	2,429.8	(109.7)
Net Income Attributable to Air Products
Income from continuing operations	304.4	278.9	556.0	559.8
Income (Loss) from discontinued operations	1,825.6	(752.2)	1,873.8	(669.5)
Net Income (Loss) Attributable to Air Products	$ 2,130.0	$ (473.3)	$ 2,429.8	$ (109.7)
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations, basic (in dollars per share)	$ 1.40	$ 1.29	$ 2.55	$ 2.59
Income from discontinued operations, basic (in dollars per share)	8.38	(3.48)	8.61	(3.10)
Net Income Attributable to Air Products (in dollars per share)	9.78	(2.19)	11.16	(0.51)
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations, diluted (in dollars per share)	1.39	1.28	2.53	2.57
Income from discontinued operations, diluted (in dollars per share)	8.31	(3.45)	8.53	(3.08)
Net Income Attributable to Air Products (in dollars per share)	$ 9.70	$ (2.17)	$ 11.06	$ (0.51)
Weighted Average Common Shares - Basic (in millions)	217.9	216.1	217.8	215.9
Weighted Average Common Shares - Diluted (in millions)	219.7	217.9	219.6	217.8
Dividends Declared Per Common Share - Cash (in dollars per share)	$ 0.95	$ 0.86	$ 1.81	$ 1.67