Regulatory Assets and Liabilities, Regulatory Assets (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Regulatory Assets [Line Items]
Regulatory Asset, Current		$ 30	$ 217
Regulatory Asset, Noncurrent		349	359
Regulatory assets not currently earning a return		123	48
Pension and Retiree Medical Obligations
Regulatory Assets [Line Items]
Regulatory Asset, Current		2	2	[1]
Regulatory Asset, Noncurrent		147	146	[1]
Excess deferred taxes - TCJA
Regulatory Assets [Line Items]
Regulatory Asset, Current		1	1	[1]
Regulatory Asset, Noncurrent		47	48	[1]
Recoverable Deferred Taxes on AFUDC Recorded in Plant
Regulatory Assets [Line Items]
Regulatory Asset, Current		0	0	[1]
Regulatory Asset, Noncurrent		44	40	[1]
Net AROs
Regulatory Assets [Line Items]
Regulatory Asset, Current	[2]	0	0	[1]
Regulatory Asset, Noncurrent	[2]	59	48	[1]
Losses on Reacquired Debt
Regulatory Assets [Line Items]
Regulatory Asset, Current		1	1	[1]
Regulatory Asset, Noncurrent		18	19	[1]
Deferred Fuel Costs
Regulatory Assets [Line Items]
Regulatory Asset, Current		0	136	[1]
Regulatory Asset, Noncurrent		0	34	[1]
Other
Regulatory Assets [Line Items]
Regulatory Asset, Current		26	77	[1]
Regulatory Asset, Noncurrent		$ 34	$ 24	[1]

[1] Prior period amounts have been restated to conform with current year presentation.

[2] Includes amounts recorded for future recovery of AROs.