Risk Management and Hedging Activities - PAC - Balance Sheet Location (Details) - PAC - Commodity derivatives - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Total	$ 223		$ 53
Cash collateral payable	(64)		5
Total derivatives - net basis	159		58
Derivative Contracts - Current Assets
Derivatives, Fair Value [Line Items]
Total	182		76
Cash collateral payable	(55)		0
Total derivatives - net basis	127		76
Other Assets
Derivatives, Fair Value [Line Items]
Total	80		20
Cash collateral payable	(9)		0
Total derivatives - net basis	71		20
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Total	(35)		(36)
Cash collateral payable	0		5
Total derivatives - net basis	(35)		(31)
Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Total	(4)		(7)
Cash collateral payable	0		0
Total derivatives - net basis	(4)		(7)
Not Designated as Hedging
Derivatives, Fair Value [Line Items]
Derivative asset, gross	272		104
Derivative liability	(49)		(51)
Total	223		53
Net regulatory asset (liability) on derivative contracts	(223)	$ (195)	(53)	$ (102)	$ 0	$ 17
Not Designated as Hedging | Derivative Contracts - Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross	183		81
Derivative liability	(1)		(5)
Total	182		76
Not Designated as Hedging | Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross	80		21
Derivative liability	0		(1)
Total	80		20
Not Designated as Hedging | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative asset, gross	9		2
Derivative liability	(44)		(38)
Total	(35)		(36)
Not Designated as Hedging | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative asset, gross	0		0
Derivative liability	(4)		(7)
Total	$ (4)		$ (7)