Financing Agreements (Schedule of Fair Value) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Sep. 30, 2018
Debt Instrument [Line Items]
Total	$ 1,787.5	$ 1,766.1
Unsecured Debentures [Member]
Debt Instrument [Line Items]
Fair value of unsecured notes	44.1	42.9
Senior Secured Term Loan A [Member]
Debt Instrument [Line Items]
Senior secured Term Loan A	999.5	991.9
Senior Unsecured 5.75% Notes due on September 1, 2023 [Member]
Debt Instrument [Line Items]
Fair value of unsecured notes	438.6	437.3
Senior Unsecured 5.00% Notes due on February 14, 2025 [Member]
Debt Instrument [Line Items]
Fair value of unsecured notes	$ 305.3	$ 294.0