Consolidated Comprehensive Income Statements (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)	$ 2,135.7	$ (465.5)	$ 2,442.1	$ (93.5)
Translation adjustments, net of tax	149.6	139.9	(131.6)	37.0
Net gain (loss) on derivatives, net of tax	(15.4)	12.8	(25.2)	28.8
Pension and postretirement benefits, net of tax	3.8	0.0	3.8	0.0
Reclassification adjustments:
Currency translation adjustment	49.1	0.4	49.1	2.8
Derivatives, net of tax	5.8	(11.1)	31.4	(30.4)
Pension and postretirement benefits, net of tax	30.1	22.7	57.5	43.8
Total Other Comprehensive Income (Loss)	223.0	164.7	(15.0)	82.0
Comprehensive Income (Loss)	2,358.7	(300.8)	2,427.1	(11.5)
Net Income Attributable to Noncontrolling Interests	5.7	7.8	12.3	16.2
Other Comprehensive Income Attributable to Noncontrolling Interests	5.0	2.8	1.9	2.8
Comprehensive Income (Loss) Attributable to Air Products	$ 2,348.0	$ (311.4)	$ 2,412.9	$ (30.5)