NEW ACCOUNTING STANDARDS (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	[1]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sundry	$ 309		$ 249
Property, plant and equipment, net	35,520		34,439
Right-of-use assets – operating leases	595
Deferred income tax assets	157		141
Other current liabilities	914		935
Deferred credits and other	2,049		1,493
Retained earnings	10,966		10,104
Regulatory liabilities	3,823		4,016
Accumulated other comprehensive income (loss)	(978)		(764)
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sundry		$ (71)
Property, plant and equipment, net		(147)
Right-of-use assets – operating leases		603
Deferred income tax assets		(3)
Other current liabilities		80
Long-term debt		(138)
Deferred credits and other		436
Retained earnings		17
Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		40
Regulatory liabilities		2
Accumulated other comprehensive income (loss)		42
San Diego Gas and Electric Company [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sundry	25		5
Property, plant and equipment, net	16,611		16,310
Right-of-use assets – operating leases	126
Other current liabilities	268		141
Deferred credits and other	686		488
Retained earnings	5,271		4,687
Regulatory liabilities	2,400		2,404
Accumulated other comprehensive income (loss)	(11)		(10)
San Diego Gas and Electric Company [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sundry		0
Property, plant and equipment, net		0
Right-of-use assets – operating leases		130
Deferred income tax assets		0
Other current liabilities		20
Long-term debt		0
Deferred credits and other		110
Retained earnings		0
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]
Sundry	39		31
Property, plant and equipment, net	12,963		12,439
Right-of-use assets – operating leases	99
Other current liabilities	223		217
Deferred credits and other	422		330
Retained earnings	3,679		3,390
Regulatory liabilities	1,423		1,612
Accumulated other comprehensive income (loss)	$ (19)		$ (20)
Southern California Gas Company [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sundry		0
Property, plant and equipment, net		0
Right-of-use assets – operating leases		116
Deferred income tax assets		0
Other current liabilities		23
Long-term debt		0
Deferred credits and other		93
Retained earnings		0
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 liabilities		2
Accumulated other comprehensive income (loss)		4
Disposal Group Held-for-sale [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets held for sale		13
Disposal Group Held-for-sale [Member] | San Diego Gas and Electric Company [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets held for sale		0
Disposal Group Held-for-sale [Member] | Southern California Gas Company [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets held for sale		$ 0

[1] Derived from audited financial statements.