EMPLOYEE BENEFIT PLANS - SAVINGS PLANS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Savings Plan [Line Items]
Employer contributions to defined benefit plan	$ 47	$ 44	$ 43
Market value of employer stock held by plan	1,100	1,300
San Diego Gas and Electric Company [Member]
Savings Plan [Line Items]
Employer contributions to defined benefit plan	16	15	15
Southern California Gas Company [Member]
Savings Plan [Line Items]
Employer contributions to defined benefit plan	$ 25	$ 24	$ 23