Consolidated Income Statements - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Sales	$ 1,882.5	$ 1,866.3
Cost of sales	1,318.1	1,295.9
Selling and administrative	165.7	173.9
Research and development	15.1	16.9
Business separation costs	30.2	12.0
Cost reduction and asset actions	50.0	0.0
Other income (expense), net	24.7	4.9
Operating Income	328.1	372.5
Equity affiliates’ income	38.0	33.3
Interest expense	29.5	22.2
Income From Continuing Operations Before Taxes	336.6	383.6
Income tax provision	78.4	96.4
Income from Continuing Operations	258.2	287.2
Income From Discontinued Operations, net of tax	48.2	84.8
Net Income	306.4	372.0
Net Income Attributable to Noncontrolling Interests of Continuing Operations	6.6	6.3
Net Income Attributable to Noncontrolling Interests of Discontinued Operations	0.0	2.1
Net Income Attributable to Air Products	299.8	363.6
Net Income Attributable to Air Products
Income from continuing operations	251.6	280.9
Income from discontinued operations	48.2	82.7
Net Income Attributable to Air Products	$ 299.8	$ 363.6
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations, basic (in dollars per share)	$ 1.16	$ 1.30
Income from discontinued operations, basic (in dollars per share)	0.22	0.38
Net Income Attributable to Air Products (in dollars per share)	1.38	1.68
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations, diluted (in dollars per share)	1.15	1.29
Income from discontinued operations, diluted (in dollars per share)	0.22	0.38
Net Income Attributable to Air Products (in dollars per share)	$ 1.37	$ 1.67
Weighted Average Common Shares - Basic (in millions)	217.7	215.8
Weighted Average Common Shares - Diluted (in millions)	219.7	217.6
Dividends Declared Per Common Share - Cash	$ 0.86	$ 0.81