Leases - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Millions	2 Months Ended	7 Months Ended	9 Months Ended
	Sep. 30, 2023	Aug. 11, 2023	Sep. 30, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating - operating cash flows	$ 11.8
Finance - financing cash flows	0.5
Finance - operating cash flows	0.1
ROU lease assets obtained in the exchange for lease liabilities:
Operating leases	0.8	$ 19.2	$ 24.7
Finance leases	$ 0.0	0.6	6.6
Predecessor
Cash paid for amounts included in the measurement of lease liabilities:
Operating - operating cash flows		43.3	57.7
Finance - financing cash flows		2.5	3.1
Finance - operating cash flows		$ 0.5	$ 0.5