Variable Interest Entities (Trusts) (Details) - SCE - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2021
Variable Interest Entity [Line Items]
Common stock	$ 2,168,000,000							$ 2,168,000,000
Trust Securities [Member]
Variable Interest Entity [Line Items]
Liquidation value (in dollars per share)			$ 2,500
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Liquidation value (in dollars per share)			$ 25
Common stock	10,000		$ 10,000					10,000
Power Purchase Agreement
Variable Interest Entity [Line Items]
Amount of related party transaction	106,000,000	$ 159,000,000
Trust II
Variable Interest Entity [Line Items]
Liquidation preference							$ 400,000,000
Trust II | Trust Securities [Member]
Variable Interest Entity [Line Items]
Liquidation preference	220,000,000							220,000,000
Trust II | 5.10% Series G Preferred Stock
Variable Interest Entity [Line Items]
Security dividend rate, (as a percent)							5.10%
Liquidation preference	220,000,000						$ 400,000,000	220,000,000
Trust III
Variable Interest Entity [Line Items]
Liquidation preference						$ 275,000,000
Trust III | Trust Securities [Member]
Variable Interest Entity [Line Items]
Liquidation preference	275,000,000							275,000,000
Trust III | 5.75% Series H Preferred Stock
Variable Interest Entity [Line Items]
Security dividend rate, (as a percent)						5.75%
Liquidation preference	275,000,000					$ 275,000,000		275,000,000
Trust IV
Variable Interest Entity [Line Items]
Liquidation preference					$ 325,000,000
Trust IV | Trust Securities [Member]
Variable Interest Entity [Line Items]
Liquidation preference	325,000,000							325,000,000
Trust IV | 5.375% Series J Preferred Stock
Variable Interest Entity [Line Items]
Security dividend rate, (as a percent)					5.375%
Liquidation preference	325,000,000				$ 325,000,000			325,000,000
Trust V
Variable Interest Entity [Line Items]
Liquidation preference				$ 300,000,000
Trust V | Trust Securities [Member]
Variable Interest Entity [Line Items]
Liquidation preference	300,000,000							300,000,000
Trust V | 5.45% Series K Preferred Stock
Variable Interest Entity [Line Items]
Security dividend rate, (as a percent)				5.45%
Liquidation preference	300,000,000			$ 300,000,000				300,000,000
Trust VI
Variable Interest Entity [Line Items]
Liquidation preference			$ 475,000,000
Trust VI | Trust Securities [Member]
Variable Interest Entity [Line Items]
Liquidation preference	475,000,000							475,000,000
Trust VI | 5.00% Series L Preferred Stock
Variable Interest Entity [Line Items]
Security dividend rate, (as a percent)			5.00%
Liquidation preference	$ 475,000,000		$ 475,000,000					$ 475,000,000