Commodity Derivatives (Details) MWh in Millions, MMBTU in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023 USD ($) MMBTU MWh	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) MMBTU MWh	Jun. 30, 2022 USD ($)	Dec. 31, 2022 MMBTU MWh
Other Derivative Instruments
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ (19)	$ 97	$ (108)	$ 103
Electric Commodity [Member]
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional Amount | MWh	[1],[2]	93		93		61
Cash Flow Hedges
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative Instruments in Hedges, at Fair Value, Net		$ 0		$ 0
Natural Gas Commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional Amount | MMBTU	[1],[2]	110		110		131
Natural Gas Commodity | Other Derivative Instruments
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ 0	$ (1)	$ 3	$ 3

[1] Not reflective of net positions in the underlying commodities.

[2] Notional amounts for options included on a gross basis but weighted for the probability of exercise.