Commodity Derivatives (Details) MWh in Millions, MMBTU in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2024 USD ($) MMBTU MWh	Mar. 31, 2023 USD ($)	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		$ 3	$ (89)
Cash Flow Hedge Commodity [Member]
Derivative [Line Items]
Commodity contracts designated as cash flow hedges		$ 0
Electric Commodity [Member]
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional Amount | MWh	[1],[2]	35		48
Natural Gas Commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional Amount | MMBTU	[1],[2]	78		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		$ 4	$ 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.