Pension Plans - Schedule of Net Benefit Costs (Details) - Pension Plan - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 0.4	$ 0.3	$ 0.8	$ 0.6
Interest Cost	5.4	6.7	10.8	13.4
Expected return on plan assets	(10.6)	(10.7)	(21.2)	(21.3)
Amortization of unrecognized net losses	2.1	1.6	4.1	3.2
Settlement charge	0.0	0.1	0.0	0.2
Net periodic benefit credit	$ (2.7)	$ (2.0)	$ (5.5)	$ (3.9)