Net Income Per Unrestricted Share - Reconciliation of Numerator and Denominator Used in Calculation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Net Loss	$ (146.3)	$ (74.8)	$ (323.5)	$ (233.3)
Dilutive Effect on Income of Equity-based Compensation Equivalent Shares	0.0	0.0	0.0	0.0
Diluted Net Loss Attributed to Unrestricted Shares	$ (146.3)	$ (74.8)	$ (323.5)	$ (233.3)
Weighted-Average Unrestricted Shares Outstanding (in shares)	64,056,900	63,852,800	64,004,400	63,804,400
Equity-based Compensation Equivalent Shares (in shares)	0	0	0	0
Weighted-Average Unrestricted Shares and Equivalent Shares Outstanding Assuming Dilution (in shares)	64,056,900	63,852,800	64,004,400	63,804,400
Basic (in dollars per share)	$ (2.28)	$ (1.17)	$ (5.05)	$ (3.66)
Diluted (in dollars per share)	$ (2.28)	$ (1.17)	$ (5.05)	$ (3.66)
Common Stock
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Net Loss	$ (146.3)	$ (74.8)	$ (323.5)	$ (233.3)
Participating Awards
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Net Loss	$ 0.0	$ 0.0	$ 0.0	$ 0.0