Regulatory Assets and Liabilities, Regulatory Assets (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Regulatory Assets [Line Items]
Regulatory Asset, Current		$ 304	$ 411
Regulatory Asset, Noncurrent		1,267	1,277
Regulatory assets not currently earning a return		416	538
Pension and Retiree Medical Obligations
Regulatory Assets [Line Items]
Regulatory Asset, Current		2	3
Regulatory Asset, Noncurrent		396	367
Recoverable Purchased Natural Gas and Electric Energy Costs
Regulatory Assets [Line Items]
Regulatory Asset, Current		221	312
Regulatory Asset, Noncurrent		$ 22	200
Recoverable Purchased Natural Gas and Electric Energy Costs | Minimum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		3 years
Recoverable Purchased Natural Gas and Electric Energy Costs | Maximum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		1 year
Depreciation differences
Regulatory Assets [Line Items]
Regulatory Asset, Current		$ 16	16
Regulatory Asset, Noncurrent		$ 184	187
Depreciation differences | Minimum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		1 year
Depreciation differences | Maximum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		10 years
Net AROs
Regulatory Assets [Line Items]
Regulatory Asset, Current	[1]	$ 0	0
Regulatory Asset, Noncurrent	[1]	236	212
Recoverable Deferred Taxes on AFUDC Recorded in Plant
Regulatory Assets [Line Items]
Regulatory Asset, Current		0	0
Regulatory Asset, Noncurrent		135	119
Excess deferred taxes - TCJA
Regulatory Assets [Line Items]
Regulatory Asset, Current		0	2
Regulatory Asset, Noncurrent		55	54
Purchased Power Agreements
Regulatory Assets [Line Items]
Regulatory Asset, Current		4	3
Regulatory Asset, Noncurrent		20	16
Property Tax
Regulatory Assets [Line Items]
Regulatory Asset, Current		3	8
Regulatory Asset, Noncurrent		7	2
Gas pipeline inspection costs
Regulatory Assets [Line Items]
Regulatory Asset, Current		3	0
Regulatory Asset, Noncurrent		$ 25	13
Gas pipeline inspection costs | Minimum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		1 year
Gas pipeline inspection costs | Maximum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		2 years
Conservation programs
Regulatory Assets [Line Items]
Regulatory Asset, Current	[2]	$ 12	8
Regulatory Asset, Noncurrent	[2]	$ 33	16
Conservation programs | Minimum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		1 year
Conservation programs | Maximum
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		2 years
Other
Regulatory Assets [Line Items]
Regulatory Asset, Current		$ 28	39
Regulatory Asset, Noncurrent		65	43
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory Asset, Current		0	6
Regulatory Asset, Noncurrent		44	26
Grid modernization costs
Regulatory Assets [Line Items]
Regulatory Asset, Current		15	14
Regulatory Asset, Noncurrent		$ 14	22
Regulatory Asset, Amortization Period		2 years
Revenue Decoupling
Regulatory Assets [Line Items]
Regulatory Asset, Current		$ 0	0
Regulatory Asset, Noncurrent		$ 31	$ 0

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

[2] Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions.