Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2025	Mar. 31, 2024
Numerator
Income from continuing operations	$ 38.3		$ 43.3		$ 132.2	$ 77.2
Loss from discontinued operations, net of tax	(0.7)		(1.9)		(3.0)	(3.9)
Net income	$ 37.6	$ 91.6	$ 41.4	$ 31.9	$ 129.2	$ 73.3
Denominator
Weighted-average common shares outstanding (shares)	127.6		129.8		128.2	130.8
Effect of potentially dilutive securities (shares)	0.6		0.9		0.7	0.9
Weighted average diluted shares outstanding (shares)	128.2		130.7		128.9	131.7
Basic earnings (loss) per share
Continuing operations, basic earnings (loss) per share (usd per share)	$ 0.30		$ 0.33		$ 1.03	$ 0.59
Discontinued operations, basic earnings (loss) per share (usd per share)	(0.01)		(0.01)		(0.02)	(0.03)
Basic earnings per share (usd per share)	0.29		0.32		1.01	0.56
Diluted earnings (loss) per share
Continuing operations, diluted earnings (loss) per share (usd per share)	0.30		0.33		1.02	0.59
Discontinued operations, diluted earnings (loss) per share (usd per share)	(0.01)		(0.01)		(0.02)	(0.03)
Diluted earnings per share (usd per share)	$ 0.29		$ 0.32		$ 1.00	$ 0.56
Shares excluded from diluted earnings per share calculation due to anti-dilutive effect (shares)	0.1		0.1		0.1	0.2