CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 4,105	$ 2,362	$ 1,126
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total other comprehensive (loss) income	422	(140)	(133)
Preferred dividends of subsidiary	(1)	(1)	(1)
Pretax amount [Member]
Net income	5,368	2,585	1,146
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	547	(43)	(144)
Financial instruments	(146)	(161)	64
Pension and other postretirement benefits	11	25	(38)
Total other comprehensive (loss) income	412	(179)	(118)
Comprehensive income	5,780	2,406	1,028
Preferred dividends of subsidiary	(1)	(1)	(1)
Total comprehensive income, after preferred dividends of subsidiaries	5,779	2,405	1,027
Income tax (expense) benefit [Member]
Net income	(1,435)	(387)	(96)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	0	0	0
Financial instruments	33	53	(21)
Pension and other postretirement benefits	1	(7)	4
Total other comprehensive (loss) income	34	46	(17)
Comprehensive income	(1,401)	(341)	(113)
Preferred dividends of subsidiary	0	0	0
Total comprehensive income, after preferred dividends of subsidiaries	(1,401)	(341)	(113)
Net-of-tax amount [Member]
Net income	3,933	2,198	1,050
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	547	(43)	(144)
Financial instruments	(113)	(108)	43
Pension and other postretirement benefits	12	18	(34)
Total other comprehensive (loss) income	446	(133)	(135)
Comprehensive income	4,379	2,065	915
Preferred dividends of subsidiary	(1)	(1)	(1)
Total comprehensive income, after preferred dividends of subsidiaries	4,378	2,064	914
Noncontrolling interests (after-tax) [Member]
Net income	172	164	76
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	(12)	3	(11)
Financial instruments	(12)	(10)	13
Pension and other postretirement benefits	0	0	0
Total other comprehensive (loss) income	(24)	(7)	2
Comprehensive income	148	157	78
Preferred dividends of subsidiary	0	0	0
Total comprehensive income, after preferred dividends of subsidiaries	148	157	78
Total [Member]
Net income	4,105	2,362	1,126
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	535	(40)	(155)
Financial instruments	(125)	(118)	56
Pension and other postretirement benefits	12	18	(34)
Total other comprehensive (loss) income	422	(140)	(133)
Comprehensive income	4,527	2,222	993
Preferred dividends of subsidiary	(1)	(1)	(1)
Total comprehensive income, after preferred dividends of subsidiaries	4,526	2,221	992
San Diego Gas and Electric Company [Member]
Net income	824	774	676
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total other comprehensive (loss) income	6	(2)	6
San Diego Gas and Electric Company [Member] | Pretax amount [Member]
Net income	1,014	938	842
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		0	0
Pension and other postretirement benefits	8	(6)	(2)
Total other comprehensive (loss) income	8	(6)	(2)
Comprehensive income	1,022	932	840
San Diego Gas and Electric Company [Member] | Income tax (expense) benefit [Member]
Net income	(190)	(171)	(173)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		0	0
Pension and other postretirement benefits	(2)	2	0
Total other comprehensive (loss) income	(2)	2	0
Comprehensive income	(192)	(169)	(173)
San Diego Gas and Electric Company [Member] | Net-of-tax amount [Member]
Net income	824	767	669
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		0	0
Pension and other postretirement benefits	6	(4)	(2)
Total other comprehensive (loss) income	6	(4)	(2)
Comprehensive income	830	763	667
San Diego Gas and Electric Company [Member] | Noncontrolling interests (after-tax) [Member]
Net income	0	7	7
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		2	8
Pension and other postretirement benefits	0	0	0
Total other comprehensive (loss) income	0	2	8
Comprehensive income	0	9	15
San Diego Gas and Electric Company [Member] | Total [Member]
Net income	824	774	676
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		2	8
Pension and other postretirement benefits	6	(4)	(2)
Total other comprehensive (loss) income	6	(2)	6
Comprehensive income	830	772	682
Southern California Gas Company [Member]
Net income	505	642	401
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total other comprehensive (loss) income	(8)	1	1
Southern California Gas Company [Member] | Pretax amount [Member]
Net income	601	762	493
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		1	1
Pension and other postretirement benefits	(12)	1
Total other comprehensive (loss) income	(12)	2	1
Comprehensive income	589	764	494
Southern California Gas Company [Member] | Income tax (expense) benefit [Member]
Net income	(96)	(120)	(92)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		0	0
Pension and other postretirement benefits	4	(1)
Total other comprehensive (loss) income	4	(1)	0
Comprehensive income	(92)	(121)	(92)
Southern California Gas Company [Member] | Net-of-tax amount [Member]
Net income	505	642	401
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Financial instruments		1	1
Pension and other postretirement benefits	(8)	0
Total other comprehensive (loss) income	(8)	1	1
Comprehensive income	$ 497	$ 643	$ 402