Financing Agreements (Schedule of Fair Value) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Total	$ 2,092.0	$ 2,172.8
Unsecured Debentures [Member]
Debt Instrument [Line Items]
Fair value of unsecured notes	44.3	46.8
Senior Secured Term Loan A [Member]
Debt Instrument [Line Items]
Senior secured Term Loan A	1,309.3	1,364.8
Senior Unsecured 5.75% Notes due on September 1, 2023 [Member]
Debt Instrument [Line Items]
Fair value of unsecured notes	440.5	449.3
Senior Unsecured 5.00% Notes due on February 14, 2025 [Member]
Debt Instrument [Line Items]
Fair value of unsecured notes	$ 297.9	$ 311.9