Balance Sheet Components (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts Receivable, Allowance for Credit Loss	$ 12		$ 12		$ 13	$ 12
Unbilled Receivables, Current	110		110			131
Finite-Lived Intangible Assets, Accumulated Amortization	541		541			499
Amortization of Intangible Assets	16	$ 15
Line of Credit Facility, Maximum Borrowing Capacity	$ 850		$ 850
Debt Instrument, Covenant Description			65.00%
Ratio of Indebtedness to Net Capital	0.543		0.543
Line of Credit Facility, Remaining Borrowing Capacity	$ 750		$ 750
Line of Credit Facility, Current Borrowing Capacity	750		750
Authorized Short-Term Debt	900		900
Purchased power and fuel	386	337	910	$ 707
Repayments of Long-term Debt			260	0
Amount above baseline net variable power costs			28
Proceeds from failed sale-leaseback transactions			0	25
Revenues	802	743	2,198	1,960
Letters of Credit Outstanding, Amount	92		92
Line of Credit, Current	220		220
Finance Lease, Liability, to be Paid	737		737
Revenues	802	$ 743	2,198	$ 1,960
Regulatory assets - noncurrent	546		546			473
Regulatory liabilities-noncurrent	1,418		1,418			1,389
Fire
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Regulatory assets - noncurrent	24		24			27
pandemic
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Increase (Decrease) in Accounts Payable and Other Operating Liabilities	16		16
Regulatory assets - noncurrent	4		4			22
wildfire
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Revenues			24
Revenues			24
Regulatory assets - noncurrent	31		31			$ 28
Letter of Credit [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Commercial paper	$ 0		$ 0