Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deferred income tax assets:
Deferred revenue	$ 53.4	$ 35.9
Stock-based compensation	5.2	0.8
Asset retirement obligation	0.0	1.7
Excess business interest expense	251.5	35.1
Lease asset liability	96.7	12.0
Settlement obligation	0.0	0.5
Debt discount and interest expense	32.2	0.1
Other intangible amortization	15.4	20.9
Postretirement and other employee benefits	21.8	0.0
Property, plant and equipment	127.8	0.0
Other	62.4	3.9
Net operating loss carryforwards	326.4	169.5
Deferred income tax assets, gross	992.8	280.4
Valuation allowance	(638.3)	0.0
Deferred income tax assets	354.5	280.4
Deferred income tax liabilities:
Property, plant and equipment	0.0	(100.3)
Goodwill and other intangible assets	(266.5)	(34.6)
Right of use asset	(100.4)	(13.5)
Other	(5.3)	(4.0)
Deferred income tax liabilities	(372.2)	(152.4)
Deferred income tax (liability) asset, net	$ (17.7)
Deferred income tax (liability) asset, net		$ 128.0