Risk Management and Hedging Activities - PAC - Balance Sheet Location (Details) - PAC - Commodity derivatives - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Total derivative asset (liability)	$ (113)	$ (76)
Cash collateral receivable	24	10
Total derivatives - net basis	(89)	(66)
Derivative Contracts - Current Assets
Derivatives, Fair Value [Line Items]
Total derivative asset (liability)	6	18
Cash collateral receivable	0	(2)
Total derivatives - net basis	6	16
Other assets
Derivatives, Fair Value [Line Items]
Total derivative asset (liability)	2	2
Cash collateral receivable	0	0
Total derivatives - net basis	2	2
Other current liabilities
Derivatives, Fair Value [Line Items]
Total derivative asset (liability)	(114)	(76)
Cash collateral receivable	24	12
Total derivatives - net basis	(90)	(64)
Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Total derivative asset (liability)	(7)	(20)
Cash collateral receivable	0	0
Total derivatives - net basis	(7)	(20)
Not Designated as Hedging
Derivatives, Fair Value [Line Items]
Derivative asset, gross	24	32
Derivative liability	(137)	(108)
Total derivative asset (liability)	(113)	(76)
Net regulatory asset (liability) on derivative contracts	113	76	$ (109)	$ (270)
Not Designated as Hedging | Derivative Contracts - Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross	6	21
Derivative liability	0	(3)
Total derivative asset (liability)	6	18
Not Designated as Hedging | Other assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross	4	2
Derivative liability	(2)	0
Total derivative asset (liability)	2	2
Not Designated as Hedging | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative asset, gross	9	7
Derivative liability	(123)	(83)
Total derivative asset (liability)	(114)	(76)
Not Designated as Hedging | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative asset, gross	5	2
Derivative liability	(12)	(22)
Total derivative asset (liability)	$ (7)	$ (20)