Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 0.7	$ 0.5
Income tax expense (benefit)	24.2	$ 24.2	$ 8.3
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	0.8
Undistributed foreign earnings	$ 52.4
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2018
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2033