SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT - FOOTNOTES (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basis of Presentation
Investment gains (losses) on Rabbi Trust		$ 41	$ 61	$ (6)
Debt Instruments [Abstract]
Current portion of long-term debt		(1,540)	(1,526)
Long-term debt		21,781	20,785
Long-term Debt, Fiscal Year Maturity [Abstract]
2021		1,504
2022		601
2023		2,031
2024		1,064
2025		811
Thereafter		16,248
Operating leases
Total operating lease commitments		698
2021		73
2022		64
2023		55
2024		51
2025		40
Thereafter		415
Parent Company [Member]
Basis of Presentation
Investment gains (losses) on Rabbi Trust		41	61	(6)
Debt Instruments [Abstract]
Gross long-term debt		8,258	10,358
Current portion of long-term debt		(850)	(1,399)
Unamortized discount on long-term debt		(32)	(35)
Unamortized debt issuance costs		(59)	(68)
Long-term debt		7,317	8,856
Long-term Debt, Fiscal Year Maturity [Abstract]
2021		850
2022		500
2023		1,000
2024		500
2025		350
Thereafter		5,100
Operating leases
Total operating lease commitments		257
2021		10
2022		11
2023		12
2024		12
2025		12
Thereafter		$ 200
Parent Company [Member] | Other Long Term Debt Due February 2020 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.40%
Gross long-term debt		$ 0	500
Parent Company [Member] | Other Long Term Debt Due March 2020 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.40%
Gross long-term debt		$ 0	500
Parent Company [Member] | Other Long Term Debt, Due November 2020 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.85%
Gross long-term debt		$ 0	400
Parent Company [Member] | Other Long-term Debt, Due January 2021 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 0	700
Proceeds from issuance of debt	$ 700
Parent Company [Member] | Other Long Term Debt, Due March 2021 [Member]
Debt Instruments [Abstract]
Fixed interest rate after floating to fixed interest rate swaps		3.069%
Gross long-term debt		$ 850	850
Parent Company [Member] | Other Long-term Debt, Due October 2022 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.875%
Gross long-term debt		$ 500	500
Parent Company [Member] | Other Long-term Debt, Due February 2023 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.90%
Gross long-term debt		$ 500	500
Parent Company [Member] | Other Long-term Debt, Due December 2023 [Member]
Debt Instruments [Abstract]
Stated percentage rate		4.05%
Gross long-term debt		$ 500	500
Parent Company [Member] | Other Long Term Debt Due June 2024 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.55%
Gross long-term debt		$ 500	500
Parent Company [Member] | Other Long-term Debt, Due November 2025 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.75%
Gross long-term debt		$ 350	350
Parent Company [Member] | Other Long Term Debt Due June 2027 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.25%
Gross long-term debt		$ 750	750
Parent Company [Member] | Other Long Term Debt Due February 2028 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.40%
Gross long-term debt		$ 1,000	1,000
Parent Company [Member] | Other Long Term Debt Due February 2038 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.80%
Gross long-term debt		$ 1,000	1,000
Parent Company [Member] | Other Long-term Debt, Due October 2039 [Member]
Debt Instruments [Abstract]
Stated percentage rate		6.00%
Gross long-term debt		$ 750	750
Parent Company [Member] | Other Long Term Debt Due February 2048 [Member]
Debt Instruments [Abstract]
Stated percentage rate		4.00%
Gross long-term debt		$ 800	800
Parent Company [Member] | Other Long-term Debt, Junior Subordinated Notes, Due July 2079 [Member]
Debt Instruments [Abstract]
Stated percentage rate		5.75%
Gross long-term debt		$ 758	758
Parent Company [Member] | Foreign exchange instruments [Member]
Basis of Presentation
Gain (loss) on settlement				(3)
PERU | Parent Company [Member] | Foreign exchange instruments [Member]
Basis of Presentation
Gain (loss) on settlement		$ 3	15
Sempra Energy [Member] | Other Long Term Debt Due February 2020 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.40%
Gross long-term debt		$ 0	500
Sempra Energy [Member] | Other Long Term Debt Due March 2020 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.40%
Gross long-term debt		$ 0	500
Sempra Energy [Member] | Other Long Term Debt, Due November 2020 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.85%
Gross long-term debt		$ 0	400
Sempra Energy [Member] | Other Long-term Debt, Due January 2021 [Member]
Debt Instruments [Abstract]
Gross long-term debt		$ 0	700
Sempra Energy [Member] | Other Long Term Debt, Due March 2021 [Member]
Debt Instruments [Abstract]
Fixed interest rate after floating to fixed interest rate swaps		3.069%
Gross long-term debt		$ 850	850
Sempra Energy [Member] | Other Long-term Debt, Due October 2022 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.875%
Gross long-term debt		$ 500	500
Sempra Energy [Member] | Other Long-term Debt, Due February 2023 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.90%
Gross long-term debt		$ 500	500
Sempra Energy [Member] | Other Long-term Debt, Due December 2023 [Member]
Debt Instruments [Abstract]
Stated percentage rate		4.05%
Gross long-term debt		$ 500	500
Sempra Energy [Member] | Other Long Term Debt Due June 2024 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.55%
Gross long-term debt		$ 500	500
Sempra Energy [Member] | Other Long-term Debt, Due November 2025 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.75%
Gross long-term debt		$ 350	350
Sempra Energy [Member] | Other Long Term Debt Due June 2027 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.25%
Gross long-term debt		$ 750	750
Sempra Energy [Member] | Other Long Term Debt Due February 2028 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.40%
Gross long-term debt		$ 1,000	1,000
Sempra Energy [Member] | Other Long Term Debt Due February 2038 [Member]
Debt Instruments [Abstract]
Stated percentage rate		3.80%
Gross long-term debt		$ 1,000	1,000
Sempra Energy [Member] | Other Long-term Debt, Due October 2039 [Member]
Debt Instruments [Abstract]
Stated percentage rate		6.00%
Gross long-term debt		$ 750	750
Sempra Energy [Member] | Other Long Term Debt Due February 2048 [Member]
Debt Instruments [Abstract]
Stated percentage rate		4.00%
Gross long-term debt		$ 800	800
Sempra Energy [Member] | Other Long-term Debt, Junior Subordinated Notes, Due July 2079 [Member]
Debt Instruments [Abstract]
Stated percentage rate		5.75%
Gross long-term debt		$ 758	758
Sempra Energy [Member] | Parent Company [Member]
Basis of Presentation
Cash dividends received		$ 300	$ 150	$ 300
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 January 2021 [Member]
Debt Instruments [Abstract]
Stated percentage rate		2.50%