Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Oct. 01, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes Summary [Line Items]
Deferred tax assets	$ 2,691,000,000		$ 1,735,000,000
Deferred tax assets, valuation allowance	343,000,000		312,000,000
Deferred tax assets, valuation allowance, increase (decrease)	31,000,000
Deferred tax assets, operating loss carryforward, limitations		$ 380,000,000			$ 54,000,000
Income taxes receivable	32,000,000		33,000,000
Unrecognized tax benefits	80,000,000		68,000,000	$ 69,000,000	$ 74,000,000
Liability for tax credits taken	14,000,000		10,000,000
Tax credits carryforward	9,000,000
Uncertain tax positions that would impact effective tax rate	47,000,000
Unrecognized tax benefits, accrued liabilities	1,000,000		0
State and local
Income Taxes Summary [Line Items]
Operating loss carryforwards	4,296,000,000
Income taxes receivable	24,000,000		$ 24,000,000
Southwestern
Income Taxes Summary [Line Items]
Deferred tax liabilities		479,000,000
Components Of Stockholders’ Equity
Income Taxes Summary [Line Items]
Deferred tax assets, valuation allowance, increase (decrease)	35,000,000
Component Of Consolidated Statements Of Operations
Income Taxes Summary [Line Items]
Deferred tax assets, valuation allowance, increase (decrease)	$ (4,000,000)
Base $2 Million Annual Limitation | Southwestern
Income Taxes Summary [Line Items]
Deferred tax assets, operating loss carryforward, limitations		2,000,000
Base $48 Million Annual Limitation | Southwestern
Income Taxes Summary [Line Items]
Deferred tax assets, operating loss carryforward, limitations		48,000,000
Base $269 Million annual limitation | Southwestern
Income Taxes Summary [Line Items]
Deferred tax assets, operating loss carryforward, limitations		$ 269,000,000