Summary of Significant Accounting Policies (Revenue Recognition) (Details) - SCE - USD ($) $ in Millions	1 Months Ended
	Jul. 31, 2021	Dec. 31, 2020	Jul. 31, 2019
Public Utilities, General Disclosures [Line Items]
Requested increase (decrease) in revenue requirement		$ 214	$ 505
2021 General Rate Case
Public Utilities, General Disclosures [Line Items]
Requested revenue requirement	$ 6,900
Requested increase (decrease) in revenue requirement	342
Non-core impairment of utility property, plant and equipment	78
Non-core impairment of utility property, plant and equipment, net of tax	$ 56