Consolidated Comprehensive Income Statements (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 490.4	$ 433.5	$ 979.3	$ 790.5
Other Comprehensive Income (Loss), net of tax:
Translation adjustments, net of tax	(398.2)	51.3	(134.2)	(16.8)
Net gain (loss) on derivatives, net of tax	(27.4)		(5.3)
Net gain (loss) on derivatives, net of tax		(35.4)		(45.7)
Pension and postretirement benefits, net of tax			0.0	(3.9)
Reclassification adjustments:
Derivatives, net of tax	(17.0)		(20.6)
Derivatives, net of tax		36.9		33.8
Pension and postretirement benefits, net of tax	21.2	18.7	40.9	33.9
Total Other Comprehensive Income (Loss)	(421.4)	71.5	(119.2)	1.3
Comprehensive Income	69.0	505.0	860.1	791.8
Net Income Attributable to Noncontrolling Interests	12.6	12.2	25.9	21.7
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	(31.8)	5.1	(16.6)	4.2
Comprehensive Income Attributable to Air Products	$ 88.2	$ 487.7	$ 850.8	$ 765.9