Income Taxes- Summary of Income Tax Benefit and Effective Income Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
(Loss) before income taxes	$ (17.5)	$ (12.0)
Income tax (benefit)	$ (4.9)	$ (3.2)
Effective income tax rate	28.00%	26.70%

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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