CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 4,105	$ 2,362	$ 1,126
Less: Income from discontinued operations, net of income tax	(1,850)	(363)	(188)
Income from continuing operations, net of income tax	2,255	1,999	938
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,666	1,569	1,491
Deferred income taxes and investment tax credits	159	189	(242)
Impairment losses	1	43	1,122
Loss (gain) on sale of assets	3	(63)	(513)
Equity earnings	(1,015)	(580)	(175)
Foreign currency transaction losses (gains), net	25	(21)	6
Share-based compensation expense	71	75	83
Other	132	47	106
Net change in other working capital components:
Accounts receivable	(315)	(91)	(145)
Income taxes receivable/payable, net	(94)	(166)	88
Inventories	(35)	(22)	32
Other current assets	38	(88)	(79)
Accounts payable	73	12	96
Regulatory balancing accounts	(231)	13	263
Reserve for Aliso Canyon costs	141	(144)	56
Other current liabilities	(127)	(99)	52
Intercompany activities with discontinued operations, net	0	378	70
Distributions from investments	651	247	202
Insurance receivable for Aliso Canyon costs	(106)	122	(43)
Wildfire fund, current and noncurrent	0	(323)	0
Reserve for Aliso Canyon costs, noncurrent	294	0	0
Changes in other noncurrent assets and liabilities, net	56	(399)	(188)
Net cash provided by continuing operations	3,642	2,698	3,220
Net cash (used in) provided by discontinued operations	(1,051)	390	296
Net cash provided by operating activities	2,591	3,088	3,516
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(4,676)	(3,708)	(3,544)
Expenditures for investments and acquisitions	(652)	(1,797)	(10,168)
Proceeds from sale of assets	19	899	1,580
Distributions from investments	761	9	10
Purchases of nuclear decommissioning trust assets	(1,439)	(914)	(890)
Proceeds from sales of nuclear decommissioning trust assets	1,439	914	890
Advances to unconsolidated affiliates	(92)	(16)	(95)
Repayments of advances to unconsolidated affiliates	7	3	3
Intercompany activities with discontinued operations, net	0	8	(22)
Other	15	21	31
Net cash used in continuing operations	(4,618)	(4,581)	(12,205)
Net cash provided by (used in) discontinued operations	5,171	(12)	(265)
Net cash provided by (used in) investing activities	553	(4,593)	(12,470)
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(1,174)	(993)	(877)
Preferred dividends paid	(157)	(142)	(89)
Proceeds from Issuance of Preferred Stock and Preference Stock	891	0	2,258
Issuances of common stock, net	11	1,830	2,272
Repurchases of common stock	(566)	(26)	(21)
Issuances of debt (maturities greater than 90 days)	6,051	4,296	8,927
Payments on debt (maturities greater than 90 days) and finance leases	(5,864)	(3,667)	(3,342)
(Decrease) increase in short-term debt, net	(1,759)	656	(84)
Advances from unconsolidated affiliates	64	155	0
Proceeds from sale of noncontrolling interests, net	26	5	90
Purchases of noncontrolling interests	(248)	(30)	(7)
Contributions from (distributions to) noncontrolling interests, net	1	98
Contributions from (distributions to) noncontrolling interests, net			(26)
Intercompany activities with discontinued operations, net	0	(266)	(109)
Other	(50)	(49)	(117)
Net cash (used in) provided by continuing operations	(2,774)	1,867	8,875
Net cash provided by (used in) discontinued operations	401	(392)	(25)
Net cash (used in) provided by financing activities	(2,373)	1,475	8,850
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0	0	(2)
Effect of exchange rate changes in discontinued operations	(3)	1	(12)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3)	1	(14)
Increase (decrease) in cash, cash equivalents and restricted cash, including discontinued operations	768	(29)	(118)
Cash, cash equivalents and restricted cash, including discontinued operations, January 1	217	246	364
Cash, cash equivalents and restricted cash, including discontinued operations, December 31	985	217	246
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	1,046	1,051	773
Income tax payments (refunds), net	1,385	360	174
Noncash acquisition of businesses:
Assets acquired	0	0	9,670
Liabilities assumed	0	0	(102)
Cash paid	0	0	(9,568)
Other Noncash Investing and Financing Items [Abstract]
Accrued interest receivable from unconsolidated affiliate	0	55	62
Accrued capital expenditures	535	515	425
Accrued commercial paper proceeds	0	67	0
Increase in finance lease obligations for investment in property, plant and equipment	77	38	556
Increase in ARO for investment in PP&E	142	36	78
Debt instrument converted	22	0	0
Contribution to Cameron LNG JV	50	0	0
Distribution from Cameron LNG JV	50	0	0
Common dividends issued in stock	22	55	54
San Diego Gas and Electric Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	824	774	676
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	801	760	688
Deferred income taxes and investment tax credits	35	105	39
Other	27	13	(17)
Net change in other working capital components:
Accounts receivable	(134)	(15)	30
Due to/from affiliates, net	11	(8)	(2)
Income taxes receivable/payable, net	129	(126)	23
Inventories	(10)	4	3
Other current assets	4	(19)	(6)
Accounts payable	31	32	(1)
Regulatory balancing accounts	(71)	(101)	138
Other current liabilities	(100)	4	4
Wildfire fund, current and noncurrent	0	(323)	0
Changes in other noncurrent assets and liabilities, net	(158)	(10)	9
Net cash provided by operating activities	1,389	1,090	1,584
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(1,942)	(1,522)	(1,542)
Decrease in cash from deconsolidation of Otay Mesa VIE	0	(8)	0
Purchases of nuclear decommissioning trust assets	(1,439)	(914)	(890)
Proceeds from sales of nuclear decommissioning trust assets	1,439	914	890
Other	8	8	0
Net cash provided by (used in) investing activities	(1,934)	(1,522)	(1,542)
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(200)	0	(250)
Equity contribution from Sempra Energy	0	322	0
Issuances of debt (maturities greater than 90 days)	1,598	400	618
Payments on debt (maturities greater than 90 days) and finance leases	(510)	(274)	(492)
(Decrease) increase in short-term debt, net	(80)	(211)	38
Contributions from (distributions to) noncontrolling interests, net	0	172	57
Debt issuance costs	(11)	(4)	(5)
Net cash (used in) provided by financing activities	797	405	(34)
Increase (decrease) in cash, cash equivalents and restricted cash, including discontinued operations	252	(27)	8
Cash, cash equivalents and restricted cash, January 1	10	37	29
Cash, cash equivalents and restricted cash, December 31	262	10	37
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	404	405	214
Income tax payments (refunds), net	25	191	112
Other Noncash Investing and Financing Items [Abstract]
Accrued capital expenditures	199	174	159
Increase in finance lease obligations for investment in property, plant and equipment	30	16	550
Increase in ARO for investment in PP&E	31	(1)	35
Southern California Gas Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	505	642	401
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	654	602	556
Deferred income taxes and investment tax credits	(112)	88	78
Impairment losses	0	37	0
Other	59	(5)	(7)
Net change in other working capital components:
Accounts receivable	(101)	(73)	(87)
Due to/from affiliates, net	(27)	(1)	(10)
Income taxes receivable/payable, net	189	(156)	14
Inventories	(19)	1	(2)
Other current assets	(12)	(9)	11
Accounts payable	64	(7)	71
Regulatory balancing accounts	(160)	114	125
Reserve for Aliso Canyon costs	141	(144)	56
Other current liabilities	(21)	(21)	(6)
Insurance receivable for Aliso Canyon costs	(106)	122	(43)
Reserve for Aliso Canyon costs, noncurrent	294	0	0
Changes in other noncurrent assets and liabilities, net	178	(322)	(144)
Net cash provided by operating activities	1,526	868	1,013
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(1,843)	(1,439)	(1,538)
Other	0	1	7
Net cash provided by (used in) investing activities	(1,843)	(1,438)	(1,531)
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(100)	(150)	(50)
Preferred dividends paid	(1)	(1)	(1)
Issuances of debt (maturities greater than 90 days)	949	349	949
Payments on debt (maturities greater than 90 days) and finance leases	(12)	(6)	(500)
(Decrease) increase in short-term debt, net	(517)	374	140
Debt issuance costs	(8)	(4)	(10)
Net cash (used in) provided by financing activities	311	562	528
Increase (decrease) in cash, cash equivalents and restricted cash, including discontinued operations	(6)	(8)	10
Cash, cash equivalents and restricted cash, January 1	10	18	8
Cash, cash equivalents and restricted cash, December 31	4	10	18
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	146	126	105
Income tax payments (refunds), net	19	188	0
Other Noncash Investing and Financing Items [Abstract]
Accrued capital expenditures	208	205	191
Increase in finance lease obligations for investment in property, plant and equipment	47	22	6
Increase in ARO for investment in PP&E	107	35	35
Preferred Stock [Member]
Other Noncash Investing and Financing Items [Abstract]
Dividends declared but not paid	47	36	36
Common Stock [Member]
Other Noncash Investing and Financing Items [Abstract]
Dividends declared but not paid	$ 301	$ 283	$ 245