Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Regulatory Assets [Line Items]
Total regulatory assets	$ 5,062	$ 3,963
Regulatory assets, current	1,319	544
Regulatory assets, noncurrent	3,743	3,419
Regulatory assets not earning a return on investment	$ 2,300	1,800
Deferred net power costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	1 year
Total regulatory assets	$ 1,478	531
Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory asset, amortization period	15 years
Total regulatory assets	$ 835	742
Employee benefit plans
Regulatory Assets [Line Items]
Regulatory asset, amortization period	14 years
Total regulatory assets	$ 490	472
Deferred income taxes
Regulatory Assets [Line Items]
Total regulatory assets	373	342
Asset disposition costs
Regulatory Assets [Line Items]
Total regulatory assets	$ 231	285
Demand side management
Regulatory Assets [Line Items]
Regulatory asset, amortization period	10 years
Total regulatory assets	$ 224	211
Levelized depreciation
Regulatory Assets [Line Items]
Regulatory asset, amortization period	28 years
Total regulatory assets	$ 151	135
Unrealized losses on regulated derivative contracts
Regulatory Assets [Line Items]
Regulatory asset, amortization period	1 year
Total regulatory assets	$ 112	157
Environmental costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	30 years
Total regulatory assets	$ 111	108
Wildfire mitigation and vegetation management costs
Regulatory Assets [Line Items]
Total regulatory assets	$ 111	21
Deferred operating costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	10 years
Total regulatory assets	$ 83	103
Other
Regulatory Assets [Line Items]
Total regulatory assets	$ 863	$ 856