Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Components of Basic and Diluted Earnings per Share [Abstract]
Net Income (Loss)	$ 184.0	$ 161.5	$ 153.1
Weighted-average shares outstanding - basic (in shares)	52.6	52.4	52.3
Effect of dilutive securities (in shares)	1.3	1.0	0.5
Weighted-average shares outstanding - diluted (in shares)	53.9	53.4	52.8
Earnings per share:
Net earnings per share - basic (in dollars per share)	$ 3.50	$ 3.08	$ 2.93
Net earnings per share - diluted (in dollars per share)	$ 3.42	$ 3.03	$ 2.90
Antidilutive securities excluded from computation of earnings per share (in shares)	0.0	0.0
Stock Options
Earnings per share:
Antidilutive securities excluded from computation of earnings per share (in shares)			0.5
Restricted Stock
Earnings per share:
Antidilutive securities excluded from computation of earnings per share (in shares)			0.2