Accumulated Other Comprehensive Income (Loss) Rollforward (Details) - USD ($)	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	$ (32.8)		$ (33.1)
Other comprehensive loss	0.3	$ (2.2)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	(30,200,000)		(30,500,000)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	300,000
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	(2,600,000)		(2,600,000)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	(32,800,000)		$ (33,100,000)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	300,000
Other comprehensive loss	$ 0.3	$ (2.2)