Pension Plans - Schedule of Net Benefit Costs (Details) - Pension Plan - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
U.S.
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 0.0	$ 0.0
Interest Cost	5.1	4.7
Expected return on plan assets	(6.5)	(7.5)
Amortization of unrecognized net losses	1.0	1.0
Settlement charge	0.0	0.1
Net periodic (benefit)/cost	(0.4)	(1.7)
International
Defined Benefit Plan Disclosure [Line Items]
Service Cost	0.1	0.2
Interest Cost	0.7	1.1
Expected return on plan assets	(1.2)	(1.6)
Amortization of unrecognized net losses	0.3	0.5
Settlement charge	0.0	0.0
Net periodic (benefit)/cost	$ (0.1)	$ 0.2