Commodity Derivatives (Details) MWh in Millions, MMBTU in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024 USD ($) MMBTU MWh	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) MMBTU MWh	Jun. 30, 2023 USD ($)	Dec. 31, 2023 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		$ 41	$ (19)	$ 44	$ (108)
Cash Flow Hedge Commodity [Member]
Derivative [Line Items]
Commodity contracts designated as cash flow hedges		$ 0		$ 0
Electric Commodity [Member]
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional Amount | MWh	[1],[2]	75		75		48
Natural Gas Commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional Amount | MMBTU	[1],[2]	79		79		84
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		$ (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.