Consolidated Comprehensive Income Statements (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 477.1	$ 490.4	$ 963.8	$ 979.3
Other Comprehensive Income (Loss), net of tax
Translation adjustments, net of tax	(144.6)	(398.2)	271.1	(134.2)
Net gain (loss) on derivatives, net of tax	(5.2)	(27.4)	8.6	(5.3)
Reclassification adjustments:
Derivatives, net of tax	36.0	(17.0)	34.7	(20.6)
Pension and postretirement benefits, net of tax	18.3	21.2	36.6	40.9
Total Other Comprehensive Loss	(95.5)	(421.4)	351.0	(119.2)
Comprehensive Income	381.6	69.0	1,314.8	860.1
Net Income Attributable to Noncontrolling Interests	4.0	12.6	8.7	25.9
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	15.6	(31.8)	35.3	(16.6)
Comprehensive Income Attributable to Air Products	$ 362.0	$ 88.2	$ 1,270.8	$ 850.8