Taxes on Income - Reconciliation of the Amount of Tax Expense at the Federal Statutory Rate and Taxes on Income (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Federal taxes at statutory rate		$ 513.3	$ 213.8	$ 346.0
Federal statutory rate		21.00%	21.00%	21.00%
Transition tax on deemed repatriation of undistributed foreign earnings		$ 0.0	$ 0.0	$ 86.0
Transition tax on deemed repatriation of undistributed foreign earnings percent		0	0	0.052
State taxes, net of federal tax effect		$ 60.8	$ 28.2	$ 29.7
State taxes, net of federal tax effect rate		2.50%	2.80%	1.80%
Tax reserve release on audit settlement, net of valuation allowance	[1]	$ (126.8)	$ 0.0	$ 0.0
Tax reserve release on audit settlement, net of valuation allowance rate	[1]	(5.20%)	0.00%	0.00%
Effect of net income (loss) attributable to noncontrolling interests		$ (55.3)	$ 2.5	$ (2.1)
Effect of net income attributable to noncontrolling interest rate		(2.30%)	0.20%	(0.10%)
Effect of non-U.S. operations		$ (30.4)	$ 6.9	$ (21.3)
Effect of non-U.S. operation rate		(1.20%)	0.70%	(1.30%)
Capital loss on investment, net of valuation allowance	[2]	$ (12.4)	$ (27.0)	$ 0.0
Capital loss on investment, net of valuation allowance rate	[2]	(0.50%)	(2.70%)	0.00%
Other		$ 0.4	$ 6.4	$ 4.0
Other rate		0.00%	0.70%	0.20%
Tax Provision		$ 349.6	$ 230.8	$ 442.3
Effective Tax Rate		14.30%	22.70%	26.80%

[1] The Company released a tax reserve in fiscal year 2021 following the close of an IRS audit of the transition tax for fiscal year 2018.

[2] The Company recognized a tax benefit in fiscal years 2021 and 2020 for capital losses that were realized from sales of investments. During fiscal year 2020, the sale of investments were subsequent to the change in corporate tax structure of a foreign holding company to a U.S. branch. These capital losses can be carried forward, for which the Company has assessed for realizability.