Earnings per Share (Schedule of Earnings per Share) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings Per Share
Income from continuing operations	$ 357.2	$ 297.0	$ 862.1	$ 830.1
Income from discontinued operations	127.3	29.5	166.5	69.3
Net Income Attributable to Air Products	$ 484.5	$ 326.5	$ 1,028.6	$ 899.4
Weighted average number of common shares outstanding	211.5	212.5	211.0	213.5
Employee stock options	2.3	3.8	2.7	4.0
Other award plans	0.9	1.0	0.9	0.9
Effect of dilutive securities	3.2	4.8	3.6	4.9
Weighted average number of common shares outstanding assuming dilution	214.7	217.3	214.6	218.4
Income from Continuing Operations, Basic	$ 1.69	$ 1.40	$ 4.08	$ 3.89
Income from Discontinued Operations, Basic	$ 0.60	$ 0.14	$ 0.79	$ 0.32
Basic Earnings Per Common Share Attributable to Air Products	$ 2.29	$ 1.54	$ 4.87	$ 4.21
Income from Continuing Operations, Diluted	$ 1.66	$ 1.37	$ 4.02	$ 3.80
Income from Discontinued Operations, Diluted	$ 0.60	$ 0.13	$ 0.77	$ 0.32
Diluted Earnings Per Common Share Attributable to Air Products	$ 2.26	$ 1.50	$ 4.79	$ 4.12