Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net (loss) income		$ (22.0)	$ 0.7	$ (40.9)	$ (12.1)
Net derivative gains and other costs arising during the period, net of tax expense of $0.4; $0.7; $0.4; and $1.1, respectively	[1]	1.2	1.9	1.2	2.8
Reclassification of (gains) losses into net (loss) income, net of tax (expense) benefit of $(0.4); $0.2; $(1.0); and $0.0, respectively		(0.9)	0.5	(3.3)	0.1
Other comprehensive income (loss)		0.3	2.4	(2.1)	2.9
Comprehensive (loss) income		$ (21.7)	$ 3.1	$ (43.0)	$ (9.2)

[1] Other costs include the effects of foreign currency translation adjustments which were immaterial during the periods presented.