Consolidated Comprehensive Income Statement - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss), net of tax [Abstract]
Net Income	$ 1,317.6	$ 993.1	$ 1,032.5
Translation adjustments, net of tax	(699.3)	(213.1)	(25.0)
Net gain (loss) on derivatives, net of tax	(35.0)	(15.2)	35.0
Pension and postretirement benefits, net of tax	(278.5)	(74.2)	231.9
Reclassification Adjustments [Abstract]
Currency translation adjustment	0.0	0.0	0.6
Derivatives, net of tax	20.8	(9.1)	(20.2)
Pension and postretirement benefits, net of tax	97.0	84.7	104.9
Total Other Comprehensive Income (Loss)	(895.0)	(226.9)	327.2
Comprehensive Income	422.6	766.2	1,359.7
Net income attributable to noncontrolling interests	39.7	1.4	38.3
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	(11.0)	(5.6)	(1.0)
Comprehensive Income Attributable to Air Products	$ 393.9	$ 770.4	$ 1,322.4