Consolidated Income Statements (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Sales	$ 2,187.7	$ 2,155.7	$ 4,411.7	$ 4,372.3
Cost of sales	1,474.7	1,506.5	3,018.7	3,078.3
Facility closure	0.0	0.0	29.0	0.0
Selling and administrative	190.0	194.6	379.6	386.2
Research and development	16.9	14.5	31.9	29.1
Other income (expense), net	10.4	15.3	19.0	37.4
Operating Income	516.5	455.4	971.5	916.1
Equity affiliates' income	46.2	43.7	99.1	57.5
Interest expense	35.4	30.4	72.7	60.2
Other non-operating income (expense), net	13.7	11.1	32.2	20.9
Income From Continuing Operations Before Taxes	541.0	479.8	1,030.1	934.3
Income tax provision	107.5	56.2	239.6	348.0
Income From Continuing Operations	433.5	423.6	790.5	586.3
Loss From Discontinued Operations, net of tax	0.0	0.0	0.0	(1.0)
Net Income	433.5	423.6	790.5	585.3
Net Income Attributable to Noncontrolling Interests of Continuing Operations	12.2	7.2	21.7	14.3
Net Income Attributable to Air Products	421.3	416.4	768.8	571.0
Net Income Attributable to Air Products
Income from continuing operations	421.3	416.4	768.8	572.0
Loss from discontinued operations	0.0	0.0	0.0	(1.0)
Net Income Attributable to Air Products	$ 421.3	$ 416.4	$ 768.8	$ 571.0
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations, basic (in dollars per share)	$ 1.91	$ 1.90	$ 3.49	$ 2.61
Loss from discontinued operations, basic (in dollars per share)	0	0	0	0
Net Income Attributable to Air Products (in dollars per share)	1.91	1.90	3.49	2.61
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations, diluted (in dollars per share)	1.90	1.89	3.48	2.59
Loss from discontinued operations, diluted (in dollars per share)	0	0	0	0
Net Income Attributable to Air Products (in dollars per share)	$ 1.90	$ 1.89	$ 3.48	$ 2.59
Weighted Average Common Shares - Basic (in millions)	220.2	219.4	220.0	219.2
Weighted Average Common Shares - Diluted (in millions)	221.4	220.8	221.2	220.7