Supplemental Information - Payables and Accrued Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Supplemental Balance Sheet Information [Abstract]
Trade creditors	$ 56.0	$ 41.6
Customer advances	5.3	4.0
Accrued payroll and employee benefits	41.2	33.9
Other costs associated with business separation, restructuring and cost reduction actions	7.9	0.6
Derivative Liability	1.5	0.0
Other	8.9	5.7
Total Payables and Accrued Liabilities	$ 120.8	$ 85.8