Commitments and Contingencies (Southern California Wildfires) (Details) - Southern California Edison a in Thousands, $ in Millions	3 Months Ended	5 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($)	May 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 a structure fatality
Forecast
Loss Contingencies [Line Items]
Self-insured retention per wildfire occurrence		$ 10
Wildfire-specific insurance coverage		$ 1,000	$ 0
December 2017 Wildfires
Loss Contingencies [Line Items]
Acres burned | a				280
Structures destroyed | structure				1,063
Structures damaged | structure				280
Fatalities | fatality				1
Capital expenditures	$ 46