Restructuring and Other Costs - Schedule of Reconciliation of Accruals and Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring And Other Costs [Abstract]
Additional accruals and adjustments to accruals (see table above)			$ 30.6	$ 34.4
Acquisition costs			0.2	27.9
Integration costs			15.9	22.6
Divestiture costs				0.2
Net property, plant and equipment costs			2.7	5.2
Severance and other employee costs			(0.1)	6.9
Equipment and inventory relocation costs			1.6	3.9
Facility carrying costs			1.4	2.8
Other costs			3.9	3.2
Restructuring and other costs	$ 9.7	$ 17.9	$ 56.2	$ 107.1