Other Income (Expense), Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Accumulated other comprehensive income (loss) [Line Items]
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions	$ 0.0	$ 0.0	$ (0.1)	$ 0.0
Foreign currency exchange gain (loss), net	0.1	(0.5)	0.5	(0.8)
Other, net	0.0	(0.6)	0.2	(0.7)
Other income (expense), net	$ 0.1	$ (1.1)	$ 0.6	$ (1.5)