Income Taxes (Schedule of Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Current:
United States - Federal	$ 13.5	$ 1.2	$ 42.5
State	3.0	3.0	0.1
Foreign	39.2	37.5	37.3
Total current	55.7	41.7	79.9
Deferred:
United States - Federal	(29.4)	(22.1)	4.5
State	(3.1)	(4.1)	(0.5)
Foreign	(2.3)	(7.1)	(2.2)
Total deferred	(34.8)	(33.3)	1.8
Provision for income taxes	$ 20.9	$ 8.4	$ 81.7