NEW ACCOUNTING STANDARDS - NARRATIVE (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 11,130		$ 10,104
Regulatory Liability, Noncurrent	3,741		4,016
Accumulated other comprehensive income (loss)	(939)		(764)
Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 40
Regulatory Liability, Noncurrent		2
Accumulated other comprehensive income (loss)		42
San Diego Gas and Electric Company [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	5,456		4,687
Regulatory Liability, Noncurrent	2,319		2,404
Accumulated other comprehensive income (loss)	(16)		(10)
San Diego Gas and Electric Company [Member] | Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		2
Accumulated other comprehensive income (loss)		2
Southern California Gas Company [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	3,883		3,390
Regulatory Liability, Noncurrent	1,422		1,612
Accumulated other comprehensive income (loss)	$ (23)		$ (20)
Southern California Gas Company [Member] | Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		2
Regulatory Liability, Noncurrent		2
Accumulated other comprehensive income (loss)		$ 4