Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (67)	$ (58)	$ (69)	$ (50)
Pension and PBOP – net loss:
Ending Balance	(65)	(57)	(65)	(57)
Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net loss:
Reclassified from accumulated other comprehensive loss	2	1	4	3
Other	0	0	0	(10)
Change	2	1	4	(7)
Southern California Edison | Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(37)	(27)	(39)	(23)
Pension and PBOP – net loss:
Ending Balance	(36)	(26)	(36)	(26)
Southern California Edison | Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net loss:
Reclassified from accumulated other comprehensive loss	1	1	3	2
Other	0	0	0	(5)
Change	$ 1	$ 1	$ 3	$ (3)