Restructuring and Other Costs - Schedule of Restructuring and Other Costs (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Restructuring and Related Activities [Abstract]
Restructuring	[1]	$ (1.8)	$ 7.0	$ 363.2	$ 17.7
Other		2.4	(0.1)	3.1	2.1
Restructuring and other costs		$ 0.6	$ 6.9	$ 366.3	$ 19.8

[1] The Cumulative and Total Expected columns each exclude approximately $2 million for our former Land and Development segment restructuring charges that were incurred in prior periods since the table includes no current year or prior year period activity for that segment.