Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 17,789	$ 15,949
Pension and PBOP - net loss:
Other comprehensive income, net of tax	2	2
Ending balance	17,632	17,223
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(54)	(69)
Pension and PBOP - net loss:
Other comprehensive income, net of tax	2	2
Ending balance	(52)	(67)
Accumulated Defined Benefit Plans Adjustment
Pension and PBOP - net loss:
Reclassified from accumulated other comprehensive loss	2	2
Other comprehensive income, net of tax	2	2
SCE
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	19,835	18,650
Pension and PBOP - net loss:
Other comprehensive income, net of tax	1	2
Ending balance	19,652	19,522
SCE | Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(32)	(41)
Pension and PBOP - net loss:
Other comprehensive income, net of tax	1	2
Ending balance	(31)	(39)
SCE | Accumulated Defined Benefit Plans Adjustment
Pension and PBOP - net loss:
Reclassified from accumulated other comprehensive loss	1	2
Other comprehensive income, net of tax	$ 1	$ 2