Consolidated Comprehensive Income Statement - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Other Comprehensive Income (Loss), net of tax [Abstract]
Net Income (Loss)	$ (465.5)	$ 296.9	$ (93.5)	$ 634.4
Translation adjustments, net of tax	139.9	(232.1)	37.0	(476.5)
Net gain (loss) on derivatives, net of tax	12.8	(0.4)	28.8	(24.2)
Pension and postretirement benefits, net of tax	0.0	(4.6)	0.0	(4.6)
Reclassification Adjustments [Abstract]
Currency translation adjustment	0.4	0.0	2.8	0.0
Derivatives, net of tax	(11.1)	17.6	(30.4)	31.1
Pension and postretirement benefits, net of tax	22.7	28.6	43.8	49.5
Total Other Comprehensive Income (Loss)	164.7	(190.9)	82.0	(424.7)
Comprehensive Income (Loss)	(300.8)	106.0	(11.5)	209.7
Net income attributable to noncontrolling interests	7.8	6.9	16.2	19.8
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	2.8	0.6	2.8	(4.5)
Comprehensive Income (Loss) Attributable to Air Products	$ (311.4)	$ 98.5	$ (30.5)	$ 194.4