Fair Value Measurements (Textual) (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 56,000,000		$ 31,000,000
Edison International Parent and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments		$ 0
Edison International Parent and Other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	56,000,000	$ 31,000,000
Edison International Parent and Other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term Investments	$ 5,000,000