Leases - Components of Lease Expense (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2021	Sep. 07, 2021	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease cost	$ 4.3	$ 8.1	$ 16.0	$ 14.6
Short-term lease cost	0.1	0.2	0.6	0.3
Variable lease cost	1.1	2.3	3.5	3.6
Finance lease cost:
Depreciation on leased assets	2.0	4.5	8.0	4.7
Interest on lease liabilities	1.2	2.9	3.9	3.5
Total lease cost	$ 8.7	$ 18.0	$ 32.0	$ 26.7