SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT - FOOTNOTES (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basis of Presentation
Investment gains (losses) on Rabbi Trust		$ 61	$ (6)	$ 56
New Accounting Standards
Right-of-use assets - operating leases		591
Deferred income taxes		155	141
Property, plant and equipment, net		36,452	34,439
Other current liabilities		866	935
Retained earnings		11,130	10,104
Debt Instruments [Abstract]
Current portion of long-term debt		(1,526)	(1,644)
Long-term debt		20,785	20,903
Long-term Debt, Fiscal Year Maturity [Abstract]
2020		1,501
2021		2,005
2022		594
2023		1,735
2024		1,045
Thereafter		14,367
Operating leases
Total operating lease commitments		769
2020		75
2021		75
2022		63
2023		54
2024		50
Thereafter		452
Accounting Standards Update 2016-02 [Member]
New Accounting Standards
Right-of-use assets - operating leases	$ 603
Property, plant and equipment, net	(147)
Other current liabilities	80
Retained earnings	17
Accounting Standards Update 2018-02 [Member]
New Accounting Standards
Retained earnings	40
Parent Company [Member]
Basis of Presentation
Investment gains (losses) on Rabbi Trust		61	(6)	56
New Accounting Standards
Deferred income taxes		1,766	1,554
Other current liabilities		561	527
Other long-term liabilities		667	511
Debt Instruments [Abstract]
Gross long-term debt		10,358	11,238
Build-to-suit arrangement		0	138
Current portion of long-term debt		(1,399)	(1,498)
Unamortized discount on long-term debt		(35)	(38)
Unamortized debt issuance costs		(68)	(55)
Long-term debt		8,856	9,647
Long-term Debt, Fiscal Year Maturity [Abstract]
2020		1,400
2021		1,600
2022		500
2023		1,000
2024		500
Thereafter		5,400
Operating leases
Total operating lease commitments		267
2020		10
2021		11
2022		11
2023		11
2024		12
Thereafter		212
Parent Company [Member] | Other Long-term Debt, Due February 2019 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 0	500
Stated percentage rate		9.80%
Parent Company [Member] | Other Long-term Debt, Due July 2019 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 0	500
Parent Company [Member] | Other Long-term Debt, October 2019 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 0	500
Stated percentage rate		1.625%
Parent Company [Member] | Other Long Term Debt Due February 2020 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.40%
Parent Company [Member] | Other Long Term Debt Due March 2020 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.40%
Parent Company [Member] | Other Long Term Debt, Due November 2020 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 400	400
Stated percentage rate		2.85%
Parent Company [Member] | Other Long-term Debt, Due January 2021 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 700	700
Parent Company [Member] | Other Long Term Debt, Due March 2021 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 850	850
Fixed interest rate after floating to fixed interest rate swaps		3.069%
Parent Company [Member] | Other Long-term Debt, Due October 2022 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.875%
Parent Company [Member] | Other Long-term Debt, Due February 2023 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.90%
Parent Company [Member] | Other Long-term Debt, Due December 2023 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		4.05%
Parent Company [Member] | Other Long Term Debt Due June 2024 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		3.55%
Parent Company [Member] | Other Long-term Debt, Due November 2025 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 350	350
Stated percentage rate		3.75%
Parent Company [Member] | Other Long Term Debt Due June 2027 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 750	750
Stated percentage rate		3.25%
Parent Company [Member] | Other Long Term Debt Due February 2028 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 1,000	1,000
Stated percentage rate		3.40%
Parent Company [Member] | Other Long Term Debt Due February 2038 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 1,000	1,000
Stated percentage rate		3.80%
Parent Company [Member] | Other Long-term Debt, Due October 2039 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 750	750
Stated percentage rate		6.00%
Parent Company [Member] | Other Long Term Debt Due February 2048 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 800	800
Stated percentage rate		4.00%
Parent Company [Member] | Other Long-term Debt, Junior Subordinated Notes, Due July 2079 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 758	0
Stated percentage rate		5.75%
Parent Company [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Standards
Right-of-use assets - operating leases	191
Deferred income taxes	(3)
Property, plant and equipment, net	(147)
Other current liabilities	3
Long-term debt	(138)
Other long-term liabilities	159
Retained earnings	17
Parent Company [Member] | Accounting Standards Update 2018-02 [Member]
New Accounting Standards
Tax Cuts and Jobs Act of 2017, reclassification From AOCI to retained earnings, tax effect	$ 14
Parent Company [Member] | Foreign exchange instruments [Member]
Basis of Presentation
Gain (loss) on settlement			(3)	(50)
PERU | Parent Company [Member] | Foreign exchange instruments [Member]
Basis of Presentation
Gain (loss) on settlement		$ 15
Sempra Energy [Member]
Debt Instruments [Abstract]
Build-to-suit arrangement		0	138
Sempra Energy [Member] | Other Long-term Debt, Due February 2019 [Member]
Debt Instruments [Abstract]
Gross long-term debt		0	$ 500
Stated percentage rate			9.80%
Sempra Energy [Member] | Other Long-term Debt, Due July 2019 [Member]
Debt Instruments [Abstract]
Gross long-term debt		0	$ 500
Sempra Energy [Member] | Other Long-term Debt, October 2019 [Member]
Debt Instruments [Abstract]
Gross long-term debt		0	$ 500
Stated percentage rate			1.625%
Sempra Energy [Member] | Other Long Term Debt Due February 2020 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	$ 500
Stated percentage rate		2.40%
Sempra Energy [Member] | Other Long Term Debt Due March 2020 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.40%
Sempra Energy [Member] | Other Long Term Debt, Due November 2020 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 400	400
Stated percentage rate		2.85%
Sempra Energy [Member] | Other Long-term Debt, Due January 2021 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 700	700
Sempra Energy [Member] | Other Long Term Debt, Due March 2021 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 850	850
Fixed interest rate after floating to fixed interest rate swaps		3.069%
Sempra Energy [Member] | Other Long-term Debt, Due October 2022 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.875%
Sempra Energy [Member] | Other Long-term Debt, Due February 2023 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		2.90%
Sempra Energy [Member] | Other Long-term Debt, Due December 2023 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		4.05%
Sempra Energy [Member] | Other Long Term Debt Due June 2024 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 500	500
Stated percentage rate		3.55%
Sempra Energy [Member] | Other Long-term Debt, Due November 2025 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 350	350
Stated percentage rate		3.75%
Sempra Energy [Member] | Other Long Term Debt Due June 2027 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 750	750
Stated percentage rate		3.25%
Sempra Energy [Member] | Other Long Term Debt Due February 2028 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 1,000	1,000
Stated percentage rate		3.40%
Sempra Energy [Member] | Other Long Term Debt Due February 2038 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 1,000	1,000
Stated percentage rate		3.80%
Sempra Energy [Member] | Other Long-term Debt, Due October 2039 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 750	750
Stated percentage rate		6.00%
Sempra Energy [Member] | Other Long Term Debt Due February 2048 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 800	800
Stated percentage rate		4.00%
Sempra Energy [Member] | Other Long-term Debt, Junior Subordinated Notes, Due July 2079 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 758	0
Stated percentage rate		5.75%
Sempra Energy [Member] | Parent Company [Member]
Basis of Presentation
Cash dividends received		$ 150	$ 300	$ 450
LIBOR [Member] | Parent Company [Member] | Other Long-term Debt, Due July 2019 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.69%
LIBOR [Member] | Parent Company [Member] | Other Long-term Debt, Due January 2021 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.50%
LIBOR [Member] | Sempra Energy [Member] | Other Long-term Debt, Due July 2019 [Member]
Debt Instruments [Abstract]
Stated percentage rate			2.69%
LIBOR [Member] | Sempra Energy [Member] | Other Long-term Debt, Due January 2021 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.50%