Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 284.2	$ 259.2	$ 155.9
Less: Net income allocated to participating securities	(4.9)	(4.9)	0.0
Net income available to common shareholders	$ 279.3	$ 254.3	$ 155.9
Denominator for basic earnings per share — weighted average shares	35,800	35,700	35,400
Earnings Per Share, Basic	$ 7.80	$ 7.13	$ 4.41
Less: Net income allocated to participating securities	$ (4.9)	$ (4.9)	$ 0.0
Net income available to common shareholders	$ 279.3	$ 254.3	$ 155.9
Equity compensation plans (in shares)	100	100	500
Denominator for diluted earnings per share — adjusted weighted average and assumed conversion	35,900	35,700	35,900
Diluted earnings per share (in dollars per share)	$ 7.78	$ 7.12	$ 4.35