Fair Value - Schedule of Activity for Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) (Details) - Level 3 [Member] - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Fair Value Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		$ 39	$ 45	$ 50	$ 42
Included in regulatory assets/liabilities		(2)	(1)	(11)
Recognized in net income		$ (3)	$ (2)	$ (4)	$ (1)
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Purchases and debt conversions					$ 1
Settlements				$ (1)
Ending Balance		$ 34	$ 42	34	42
Equity Investment [Member]
Fair Value Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		52	52	53	50
Recognized in net income		$ (3)	$ (2)	$ (4)	$ (1)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Purchases and debt conversions					$ 1
Ending Balance		$ 49	$ 50	$ 49	50
Natural Gas Exchange Agreements [Member]
Fair Value Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	[1]	(13)	(7)	(3)	(8)
Included in regulatory assets/liabilities	[1]	(2)	(1)	(11)
Settlements	[1]			(1)
Ending Balance	[1]	$ (15)	$ (8)	$ (15)	$ (8)

[1] There were no purchases, issuances or transfers from other categories during the periods presented in the table above.