Income Taxes - Income Tax (Benefit) Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current income tax (expense) benefit:
U.S. federal	$ (12.6)	$ (16.9)	$ (4.8)
State	(2.2)	(4.5)	(2.1)
Non-U.S.	(16.6)	(7.1)	(2.8)
Total current income tax (expense) benefit	(31.4)	(28.5)	(9.7)
Deferred income tax (expense) benefit:
U.S. federal	(13.2)	(7.3)	(13.9)
State	(3.8)	(1.8)	(7.0)
Non-U.S.	63.9	(3.8)	(13.8)
Total deferred income tax (expense) benefit	46.9	(12.9)	(34.7)
Total income tax (expense) benefit	$ 15.5	$ (41.4)	$ (44.4)