QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Selected Quarterly Financial Information [Line Items]
Revenues	$ 2,943	$ 2,758	$ 2,230	$ 2,898	$ 2,826	$ 2,565	$ 2,175	$ 2,536	$ 10,829	$ 10,102	$ 9,640
Expenses and other income	2,444	2,310	1,944	2,397	1,867	2,220	3,358	1,943
Income from continuing operations, net of income tax	429	653	357	560	913	280	(585)	330
(Loss) income from discontinued operations, net of income tax	71	256	78	(42)	51	54	55	28	328	156	(58)
Operating revenues									9,448	8,539	8,290
Net income	500	909	435	518	964	334	(530)	358	2,362	1,126	351
Earnings attributable to noncontrolling interest									(164)	(76)	(94)
Earnings attributable to common shares									$ 2,055	$ 924	$ 256
Earnings	$ 447	$ 813	$ 354	$ 441	$ 864	$ 274	$ (561)	$ 347
Earnings from continuing operations - Basic EPS (in dollars per share)	$ 1.36	$ 2.04	$ 1.03	$ 1.79	$ 3.00	$ 0.83	$ (2.29)	$ 1.26	$ 6.22	$ 2.86	$ 1.25
Basic earnings per common share (in shares)	0.21	0.89	0.26	(0.19)	0.15	0.17	0.18	0.08	$ 7.40	$ 3.45	$ 1.02
Basic earnings per common share attributable to Sempra Energy (in dollars per share)	$ 1.57	$ 2.93	$ 1.29	$ 1.60	$ 3.15	$ 1.00	$ (2.11)	$ 1.34
Weighted-average number of shares outstanding, basic (in shares)	284,600	277,400	275,000	274,700	274,300	273,900	265,800	257,900	277,904	268,072	251,545
Earnings from continuing operations - Diluted EPS (in dollars per share)	$ 1.34	$ 2.00	$ 1.01	$ 1.78	$ 2.89	$ 0.82	$ (2.29)	$ 1.25	$ 6.13	$ 2.84	$ 1.24
Diluted earnings per common share (in dollars per share)	0.21	0.84	0.25	(0.19)	0.14	0.17	0.18	0.08	$ 7.29	$ 3.42	$ 1.01
Diluted earnings per common share attributable to Sempra Energy (in dollars per share)	$ 1.55	$ 2.84	$ 1.26	$ 1.59	$ 3.03	$ 0.99	$ (2.11)	$ 1.33
Weighted-average number of shares outstanding, diluted (in shares)	288,800	295,800	279,600	277,200	296,400	275,900	265,800	259,500	282,033	269,852	252,300
Dividends on preferred stock									$ (1)	$ (1)	$ (1)
San Diego Gas and Electric Company [Member]
Selected Quarterly Financial Information [Line Items]
Operating revenues	$ 1,259	$ 1,427	$ 1,094	$ 1,145	$ 1,163	$ 1,299	$ 1,051	$ 1,055	4,925	4,568	4,476
Operating expenses	894	1,004	831	883	916	999	836	807	3,612	3,558	3,767
Operating income	365	423	263	262	247	300	215	248	1,313	1,010	709
Net income	185	266	146	177	145	216	146	169	774	676	421
Earnings attributable to noncontrolling interest	0	(3)	(3)	(1)	3	(11)	0	1	(7)	(7)	(14)
Earnings attributable to common shares	185	263	143	176	148	205	146	170	767	669	407
Southern California Gas Company [Member]
Selected Quarterly Financial Information [Line Items]
Operating revenues	1,383	975	806	1,361	1,262	802	772	1,126	4,525	3,962	3,785
Operating expenses	1,000	762	747	1,060	1,023	797	703	848	3,569	3,371	3,158
Operating income	383	213	59	301	239	5	69	278	956	591	627
Net income	204	143	31	264	156	(14)	34	225	642	401	397
Earnings attributable to common shares	204	143	30	264	156	(14)	33	225	641	400	396
Dividends on preferred stock	$ 0	$ 0	$ (1)	$ 0	$ 0	$ 0	$ (1)	$ 0	$ (1)	$ (1)	$ (1)