Commitments and Contingencies (Southern California Wildfires) (Details) - Southern California Edison a in Thousands, $ in Millions	5 Months Ended	6 Months Ended	7 Months Ended	12 Months Ended
	May 31, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 30, 2018 USD ($)	Dec. 31, 2017 USD ($) a fatality structure	May 31, 2018 USD ($)
Loss Contingencies [Line Items]
Wildfire-specific insurance coverage				$ 1,000
Self-insured retention per wildfire occurrence				$ 10	$ 10
Coverage for future periods
Loss Contingencies [Line Items]
Wildfire-specific insurance coverage	$ 940		$ 1,000
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		$ 77