Balance Sheet Components (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts Receivable, Allowance for Credit Loss	$ 13		$ 12
Unbilled Receivables, Current	115		131
Finite-Lived Intangible Assets, Accumulated Amortization	513		$ 499
Amortization of Intangible Assets	14	$ 15
Line of Credit Facility, Maximum Borrowing Capacity	$ 750
Debt Instrument, Covenant Description	65.00%
Ratio of Indebtedness to Net Capital	0.542
Line of Credit Facility, Remaining Borrowing Capacity	$ 582
Line of Credit Facility, Current Borrowing Capacity	650
Authorized Short-Term Debt	900
Purchased power and fuel	304	202
Repayments of Long-term Debt	260	0
Amount above baseline net variable power costs	13
Proceeds from failed sale-leaseback transactions	0	$ 25
Letters of Credit Outstanding, Amount	135
Tangible Asset Impairment Charges	2
Line of Credit, Current	220
Letter of Credit [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Commercial paper	$ 68