Consolidated Comprehensive Income Statements (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 457.1	$ 500.2	$ 1,436.4	$ 1,290.7
Other Comprehensive Income (Loss), net of tax:
Translation adjustments, net of tax	106.9	(48.8)	(27.3)	(65.6)
Net gain (loss) on derivatives, net of tax	23.4		18.1
Net gain (loss) on derivatives, net of tax		7.5		(38.2)
Pension and postretirement benefits, net of tax			0.0	(3.9)
Reclassification adjustments:
Currency translation adjustment	0.0	(2.6)	0.0	(2.6)
Derivatives, net of tax	(23.2)		(43.8)
Derivatives, net of tax		(13.1)		20.7
Pension and postretirement benefits, net of tax	19.8	14.8	60.7	48.7
Total Other Comprehensive Income (Loss)	126.9	(42.2)	7.7	(40.9)
Comprehensive Income	584.0	458.0	1,444.1	1,249.8
Net Income Attributable to Noncontrolling Interests	10.6	12.2	36.5	33.9
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	1.8	(5.6)	(14.8)	(1.4)
Comprehensive Income Attributable to Air Products	$ 571.6	$ 451.4	$ 1,422.4	$ 1,217.3