Business Segment Information (Reconciliation of Operating Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ 459.8	$ 561.9	$ 1,111.8	$ 1,084.9
Business and asset actions	(185.6)	0.0	(185.6)	0.0
Segment Reconciling Items
Segment Reporting Information [Line Items]
Business and asset actions	(185.6)	0.0	(185.6)	0.0
Segment Total
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ 645.4	$ 561.9	$ 1,297.4	$ 1,084.9