Balance Sheet Components Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	$ 55		$ 55		$ 54
Regulatory assets - noncurrent	546		546		473
Regulatory Liability, Current	33		33		234
Regulatory liabilities-noncurrent	1,418		1,418		1,389
Purchased power and fuel	386	$ 337	910	$ 707
Removal Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	0		0		0
Regulatory liabilities-noncurrent	1,164		1,164		1,136
Deferred Income Tax Charge [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	0		0		0
Regulatory liabilities-noncurrent	183		183		194
Asset Retirement Obligation Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	0		0		0
Regulatory liabilities-noncurrent	10		10		7
Revenue Subject to Refund [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory liabilities-noncurrent	0		0		0
Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	29		29		39
Regulatory liabilities-noncurrent	58		58		52
Regulatory Clause Revenues, under-recovered
Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	1		1		195
us-gaap_revenuerefund
Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	3		3		0
Regulatory liabilities-noncurrent	3		3		0
Deferred Derivative Gain (Loss) [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	0		0		0
Regulatory assets - noncurrent	96		96		1
Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	0		0		0
Regulatory assets - noncurrent	95		95		95
Loss on Reacquired Debt [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	0		0		0
Regulatory assets - noncurrent	20		20		21
Environmental Restoration Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	0		0		0
Regulatory assets - noncurrent	137		137		133
Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	10		10		26
Regulatory assets - noncurrent	79		79		68
Storm Costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	12		12		10
Regulatory assets - noncurrent	57		57		64
Fire
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	5		5		4
Regulatory assets - noncurrent	24		24		27
pandemic
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	12		12		0
Regulatory assets - noncurrent	4		4		22
wildfire
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	0		0		0
Regulatory assets - noncurrent	31		31		28
Deferred Fuel Costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	16		16		14
Regulatory assets - noncurrent	$ 3		$ 3		$ 14