New Accounting Guidance (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Oct. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities	$ 393.1		$ 393.1
Right-of-use assets	352.0		352.0
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities					$ 375.3
Right-of-use assets					$ 332.3
Other Non-Operating Income (Expense), Net | Accounting Standards Update 2017-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excluded components recognized within earnings	$ 7.5		$ 24.9
Interest Expense | Accounting Standards Update 2017-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excluded components recognized within earnings		$ 8.2		$ 25.6