Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 15,949	$ 15,496	$ 12,652
Pension and PBOP - net loss:
Other comprehensive income (loss), net of tax	15		(9)
Ending balance	17,789	15,949	15,496
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(69)	(69)	(50)
Pension and PBOP - net loss:
Other comprehensive income (loss), net of tax	15		(9)
Ending balance	(54)	(69)	(69)
Accumulated Defined Benefit Plans Adjustment
Pension and PBOP - net loss:
Other comprehensive income (loss) before reclassifications	7	(8)
Reclassified from accumulated other comprehensive loss	8	8
Other comprehensive income (loss), net of tax	15
SCE
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	18,650	17,827	13,785
Pension and PBOP - net loss:
Other comprehensive income (loss), net of tax	9	(2)	(11)
Ending balance	19,835	18,650	17,827
SCE | Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(41)	(39)	(23)
Pension and PBOP - net loss:
Other comprehensive income (loss), net of tax	9	(2)	(11)
Ending balance	(32)	(41)	$ (39)
SCE | Accumulated Defined Benefit Plans Adjustment
Pension and PBOP - net loss:
Other comprehensive income (loss) before reclassifications	4	(7)
Reclassified from accumulated other comprehensive loss	5	5
Other comprehensive income (loss), net of tax	$ 9	$ (2)