Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net Income (Loss) Attributable to Parent	$ 63.3	$ 2.6	$ 140.7	$ 78.4
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	(1.3)	0.0	(2.8)	0.0
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	(1.3)	0.0	(2.8)	0.0
Net Income (Loss) Available to Common Stockholders, Basic	62.0	2.6	137.9	78.4
Net Income (Loss) Available to Common Stockholders, Diluted	$ 62.0	$ 2.6	$ 137.9	$ 78.4
Denominator:
Denominator for basic earnings per share — weighted average shares	35,600	35,500	35,600	35,500
Basic earnings per share from consolidated operations (in dollars per share)	$ 1.74	$ 0.07	$ 3.88	$ 2.21
Effect of dilutive securities:
Equity compensation plans	100	500	100	500
Weighted-average shares outstanding - diluted	35,700	36,000	35,700	36,000
Diluted earnings per share (in dollars per share)	$ 1.74	$ 0.07	$ 3.87	$ 2.18