FAIR VALUE MEASUREMENTS - RECON OF LEVEL 3 ASSETS (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($) $ / MWh	Jun. 30, 2021 USD ($) $ / MWh	Jun. 30, 2022 USD ($) $ / MWh	Jun. 30, 2021 USD ($) $ / MWh
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ 58	$ 62	$ 54	$ 69
Realized and unrealized (losses) gains	(30)	8	(23)	6
Allocated transmission instruments	(6)	(2)	(6)	(2)
Settlements	11	12	8	7
Ending balance	33	80	33	80
Change in unrealized (losses) gains relating to instruments still held at June 30	(23)	14	(18)	12
Sempra Infrastructure
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	12	3	7	3
Realized and unrealized gains	6	3	14	5
Settlements	(2)	(2)	(5)	(4)
Ending balance	16	4	16	4
Change in unrealized gains (losses) relating to instruments still held at the end of the period	5	2	13	4
Sempra Infrastructure | Other current assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance	7		7
Sempra Infrastructure | Other long-term assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance	9		9
San Diego Gas and Electric Company
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	58	62	54	69
Realized and unrealized (losses) gains	(30)	8	(23)	6
Allocated transmission instruments	(6)	(2)	(6)	(2)
Settlements	11	12	8	7
Ending balance	33	80	33	80
Change in unrealized (losses) gains relating to instruments still held at June 30	$ (23)	$ 14	$ (18)	$ 12
Level 3 | San Diego Gas and Electric Company | Minimum
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Congestion revenue rights (in dollars per MWH) | $ / MWh			(3.67)	(1.81)
Market electricity forward price inputs ( in dollars per MWH) | $ / MWh	25.25	22.45	25.25	22.45
Level 3 | San Diego Gas and Electric Company | Maximum
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Congestion revenue rights (in dollars per MWH) | $ / MWh			6.96	14.11
Market electricity forward price inputs ( in dollars per MWH) | $ / MWh	125.00	151.90	125.00	151.90
Level 3 | San Diego Gas and Electric Company | Weighted Average
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Congestion revenue rights (in dollars per MWH) | $ / MWh			(0.70)	(0.12)
Market electricity forward price inputs ( in dollars per MWH) | $ / MWh	66.36	49.27	66.36	49.27