Consolidated Income Statements (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Sales	$ 2,121.9	$ 1,914.5	$ 5,984.5	$ 5,558.2
Cost of sales	1,486.2	1,320.2	4,208.1	3,829.1
Selling and administrative	184.5	168.4	528.1	510.1
Research and development	14.6	18.7	44.5	53.8
Business separation costs	0.0	9.5	30.2	28.9
Cost reduction and asset actions	42.7	13.2	103.0	23.9
Pension settlement loss	5.5	1.0	9.6	3.0
Goodwill and intangible asset impairment charge	162.1	0.0	162.1	0.0
Other income (expense), net	26.3	11.1	73.0	29.3
Operating Income	252.6	394.6	971.9	1,138.7
Equity affiliates' income (loss)	(36.9)	42.1	35.3	107.7
Interest expense	29.8	35.1	89.8	83.0
Other non-operating income (expense), net	9.8	0.0	19.5	0.0
Income From Continuing Operations Before Taxes	195.7	401.6	936.9	1,163.4
Income tax provision	89.3	145.9	262.2	335.8
Income from Continuing Operations	106.4	255.7	674.7	827.6
Income (Loss) From Discontinued Operations, net of tax	(2.3)	98.4	1,871.5	(567.0)
Net Income	104.1	354.1	2,546.2	260.6
Net Income Attributable to Noncontrolling Interests of Continuing Operations	2.2	5.4	14.5	17.5
Net Income Attributable to Noncontrolling Interests of Discontinued Operations	0.0	1.9	0.0	6.0
Net Income Attributable to Air Products	101.9	346.8	2,531.7	237.1
Net Income Attributable to Air Products
Income from continuing operations	104.2	250.3	660.2	810.1
Income (Loss) from discontinued operations	(2.3)	96.5	1,871.5	(573.0)
Net Income Attributable to Air Products	$ 101.9	$ 346.8	$ 2,531.7	$ 237.1
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations, basic (in dollars per share)	$ 0.48	$ 1.16	$ 3.03	$ 3.75
Income (Loss) from discontinued operations, basic (in dollars per share)	(0.01)	0.44	8.59	(2.65)
Net Income (Loss) Attributable to Air Products (in dollars per share)	0.47	1.60	11.62	1.10
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations, diluted (in dollars per share)	0.47	1.15	3.00	3.72
Income (Loss) from discontinued operations, diluted (in dollars per share)	(0.01)	0.44	8.52	(2.63)
Net Income (Loss) Attributable to Air Products (in dollars per share)	$ 0.46	$ 1.59	$ 11.52	$ 1.09
Weighted Average Common Shares - Basic (in millions)	218.1	216.6	217.9	216.1
Weighted Average Common Shares - Diluted (in millions)	219.8	218.5	219.8	218.0
Dividends Declared Per Common Share - Cash (in dollars per share)	$ 0.95	$ 0.86	$ 2.76	$ 2.53