Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Funds Deposited by Counterparties
Number of months beyond which company can not predict the holding of collateral (in months)	12 months
Loss Contingency
Insurance settlement		$ 7
Intangible Assets
Intangible assets, accumulated amortization	$ 3,988	3,632
Capitalized Contract Cost
Contract with customer, term	5 years
Gross Receipts and Sales Taxes
Gross receipts taxes	$ 225	216	$ 212
Purchased Energy and Other Cost of Sales for Customer Operations
Transmission and distribution charges not yet billed	276	284	240
Foreign Currency Translation and Transaction Gains and Losses
Cumulative translation adjustment	(51)	(72)	(43)
Marketing and Advertising Costs
Advertising expense	$ 239	$ 215	$ 185