Consolidated Comprehensive Income Statements (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 488.9	$ 357.0
Other Comprehensive Income (Loss), net of tax:
Translation adjustments, net of tax	264.0	(68.1)
Net gain (loss) on derivatives, net of tax	22.1
Net gain (loss) on derivatives, net of tax		(10.3)
Pension and postretirement benefits, net of tax	0.0	(3.9)
Reclassification adjustments:
Derivatives, net of tax	(3.6)
Derivatives, net of tax		(3.1)
Pension and postretirement benefits, net of tax	19.7	15.2
Total Other Comprehensive Income (Loss)	302.2	(70.2)
Comprehensive Income	791.1	286.8
Net Income Attributable to Noncontrolling Interests	13.3	9.5
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	15.2	(0.9)
Comprehensive Income Attributable to Air Products	$ 762.6	$ 278.2