Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (69)	$ (50)
Pension and PBOP – net loss:
Ending Balance	(67)	(58)
Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net loss:
Reclassified from accumulated other comprehensive loss1	2	2
Other	0	(10)
Change	2	(8)
Southern California Edison | Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(39)	(23)
Pension and PBOP – net loss:
Ending Balance	(37)	(27)
Southern California Edison | Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net loss:
Reclassified from accumulated other comprehensive loss1	2	1
Other	0	(5)
Change	$ 2	$ (4)