Commitments and Contingencies - Lease Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Fiscal Year
Operating Leases, Rent Expense	$ 41.8	$ 49.6	$ 40.8
Gross Lease Obligation [Member]
Other Commitments [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	33.7
Operating Leases, Future Minimum Payments, Due in Two Years	28.9
Operating Leases, Future Minimum Payments, Due in Three Years	22.0
Operating Leases, Future Minimum Payments, Due in Four Years	17.2
Operating Leases, Future Minimum Payments, Due in Five Years	13.7
Operating Leases, Future Minimum Payments, Due Thereafter	32.6
Operating Leases, Future Minimum Payments Due	148.1
FGL [Member] | Gross Lease Obligation [Member]
Other Commitments [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	2.0
Operating Leases, Future Minimum Payments, Due in Two Years	2.0
Operating Leases, Future Minimum Payments, Due in Three Years	2.0
Operating Leases, Future Minimum Payments, Due in Four Years	1.2
Operating Leases, Future Minimum Payments, Due in Five Years	0.0
Operating Leases, Future Minimum Payments, Due Thereafter	0.0
Operating Leases, Future Minimum Payments Due	$ 7.2