Retirement and Postretirement Plans (Defined Benefit Plans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 3.2	$ 2.8	$ 6.3	$ 5.5
Expected return on plan assets	(3.7)	(4.0)	(7.4)	(7.9)
Amortization of net loss	0.6	1.0	1.2	2.2
Net pension expense	1.2	1.0	2.3	2.2
Cost of Goods, Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.4	0.3	0.7	0.7
Selling, General and Administrative Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.7	$ 0.9	$ 1.5	$ 1.7