Cost Reduction Actions (Narrative) (Details) $ in Millions	3 Months Ended				12 Months Ended
	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($) position	Sep. 30, 2018 USD ($)
Restructuring and Related Activities [Abstract]
Cost reduction actions | $	$ 0.0	$ 25.5	$ 0.0	$ 0.0	$ 0.0	$ 25.5	$ 0.0
Number of positions eliminated or expected to be eliminated | position						300