Regulatory Matters - PAC - 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
Employee benefit plans
Regulatory Assets [Line Items]
Regulatory asset, amortization period	14 years
Total regulatory assets	$ 490	472
Deferred net power costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	1 year
Total regulatory assets	$ 1,478	531
Environmental costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	30 years
Total regulatory assets	$ 111	108
Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory asset, amortization period	15 years
Total regulatory assets	$ 835	742
Demand side management
Regulatory Assets [Line Items]
Regulatory asset, amortization period	10 years
Total regulatory assets	$ 224	211
Wildfire mitigation and vegetation management costs
Regulatory Assets [Line Items]
Total regulatory assets	111	21
PAC
Regulatory Assets [Line Items]
Total regulatory assets	1,880	1,352
Regulatory assets, current	275	65
Regulatory assets, noncurrent	1,605	1,287
Regulatory assets not earning a return on investment	$ 1,200	723
PAC | Employee benefit plans
Regulatory Assets [Line Items]
Regulatory asset, amortization period	16 years
Total regulatory assets	$ 290	286
PAC | Utah mine disposition
Regulatory Assets [Line Items]
Total regulatory assets	$ 115	116
PAC | Unamortized contract values
Regulatory Assets [Line Items]
Regulatory asset, amortization period	1 year
Total regulatory assets	$ 18	36
PAC | Deferred net power costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	2 years
Total regulatory assets	$ 546	151
PAC | Environmental costs
Regulatory Assets [Line Items]
Regulatory asset, amortization period	30 years
Total regulatory assets	$ 111	108
PAC | Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory asset, amortization period	29 years
Total regulatory assets	$ 275	241
PAC | Demand side management
Regulatory Assets [Line Items]
Regulatory asset, amortization period	10 years
Total regulatory assets	$ 224	211
PAC | Wildfire mitigation and vegetation management costs
Regulatory Assets [Line Items]
Total regulatory assets	111	21
PAC | Other
Regulatory Assets [Line Items]
Total regulatory assets	$ 190	$ 182