Risk Management and Hedging Activities - PAC - Balance Sheet Location (Details) - PAC - Commodity derivatives - USD ($) $ in Millions	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Total	$ 9		$ 270
Cash collateral receivable (payable)	0		(78)
Total derivatives - net basis	9		192
Cash collateral payable, not offset			12
Derivative Contracts - Current Assets
Derivatives, Fair Value [Line Items]
Total	51		257
Cash collateral receivable (payable)	0		(73)
Total derivatives - net basis	51		184
Other Assets
Derivatives, Fair Value [Line Items]
Total	0		20
Cash collateral receivable (payable)	0		(5)
Total derivatives - net basis	0		15
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Total	(30)		(5)
Cash collateral receivable (payable)	0		0
Total derivatives - net basis	(30)		(5)
Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Total	(12)		(2)
Cash collateral receivable (payable)	0		0
Total derivatives - net basis	(12)		(2)
Not Designated as Hedging
Derivatives, Fair Value [Line Items]
Derivative asset, gross	68		318
Derivative liability	(59)		(48)
Total	9		270
Net regulatory asset (liability) on derivative contracts	(9)	$ (109)	(270)	$ (223)	$ (195)	$ (53)
Not Designated as Hedging | Derivative Contracts - Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross	57		279
Derivative liability	(6)		(22)
Total	51		257
Not Designated as Hedging | Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross	0		27
Derivative liability	0		(7)
Total	0		20
Not Designated as Hedging | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative asset, gross	6		9
Derivative liability	(36)		(14)
Total	(30)		(5)
Not Designated as Hedging | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative asset, gross	5		3
Derivative liability	(17)		(5)
Total	$ (12)		$ (2)