Commitments and Contingencies (Upstream Lighting Program) (Details) - SCE - USD ($) $ in Millions	1 Months Ended		24 Months Ended		36 Months Ended
	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019
Upstream Lighting Program
Loss Contingencies [Line Items]
Incentives paid to manufacturers					$ 91.0
Requested manufacturer incentives refund		$ 92.0
Fines		140.0
Remedy offered	$ 21.0
Upstream Lighting Program, ESPI
Loss Contingencies [Line Items]
Incentives received			$ 1.3	$ 3.5
CPUC requested award refund		$ 33.0