Accumulated Other Comprehensive Loss (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ (235.9)	$ (148.3)
OCI before reclassifications	[1]	17.5	(11.6)
Reclassifications to earnings		1.2	(0.5)
Ending balance		(217.2)	(160.4)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(77.3)	(40.6)
OCI before reclassifications	[1]	21.5	(10.8)
Reclassifications to earnings		0.0	0.0
Ending balance		(55.8)	(51.4)
Pension and Post-retirement Activity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(159.8)	(110.3)
OCI before reclassifications	[1]	(3.3)	(0.7)
Reclassifications to earnings		1.8	0.7
Ending balance		(161.3)	(110.3)
Hedging Activity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		1.2	2.6
OCI before reclassifications	[1]	(0.7)	(0.1)
Reclassifications to earnings		(0.6)	(1.2)
Ending balance		$ (0.1)	$ 1.3

[1] OCI is defined as other comprehensive income (loss).