Summary of Significant Accounting Policies (Prepaid Insurance) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2022	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Redeemable Noncontrolling Interest [Line Items]
Wildfire Insurance Fund contributions, noncurrent			$ 2,359	$ 2,443
Wildfire Insurance Fund contributions, current			204	323
Wildfire Insurance Fund contributions			$ 95	$ 95	$ 2,457
Insurance fund contribution amortization period	15 years
Measurement Input
Redeemable Noncontrolling Interest [Line Items]
Historical term used in estimate	8 years		7 years	5 years
Wildfire Insurance Fund
Redeemable Noncontrolling Interest [Line Items]
Wildfire Insurance Fund contributions, noncurrent			$ 2,400
Wildfire Insurance Fund contributions, current			204
Wildfire Insurance Fund contributions		$ 2,400
Wildfire Insurance Fund liability, noncurrent			$ 620
Insurance fund contribution amortization period			15 years	10 years
SCE
Redeemable Noncontrolling Interest [Line Items]
Wildfire Insurance Fund contributions, noncurrent			$ 2,359	$ 2,443
Wildfire Insurance Fund contributions, current			204	323
Wildfire Insurance Fund contributions			$ 95	$ 95	$ 2,457