Earnings (Loss) per Share - Calculation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Calculation of basic earnings (loss) per share:
Net income (loss) applicable to common stock	$ (490.0)	$ 221.2	$ 418.7
Weighted-average common shares outstanding - basic (in shares)	152.1	161.2	158.7
Basic earnings (loss) per share (in dollars per share)	$ (3.22)	$ 1.37	$ 2.64
Calculation of diluted earnings (loss) per share:
Net income (loss) applicable to common stock	$ (490.0)	$ 221.2	$ 418.7
Convertible Notes	0.0	7.2	17.0
Diluted income applicable to common stock	$ (490.0)	$ 228.4	$ 435.7
Weighted-average common shares outstanding - diluted (in shares)	152.1	176.6	175.5
Diluted earnings (loss) per share (in dollars per share)	$ (3.22)	$ 1.29	$ 2.48
Effective Tax Rate	1.70%	(26.50%)	22.00%
Common Stock, Non-Exchangeable
Calculation of basic earnings (loss) per share:
Weighted-average common shares outstanding - basic (in shares)	151.5	160.6	158.6
Common Stock, Exchangeable
Calculation of basic earnings (loss) per share:
Weighted-average common shares outstanding - basic (in shares)	0.6	0.6	0.1
Convertible Notes
Calculation of diluted earnings (loss) per share:
Effective Tax Rate		21.00%	22.00%