Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Schedule of Other Assets [Line Items]
Prepaid Expense and Other Assets, Current	$ 137.6	$ 133.1
Asset Backed Loans And Other Invested Assets	35.0	226.7
Other Investments	0.0	52.2
Other assets (Note 13)	$ 172.6	$ 412.0