FAIR VALUE MEASUREMENTS - RECURRING FAIR VALUE MEASURES (Details) - Recurring - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	$ 838	$ 845
Short-term investments held in Rabbi Trust	62	55
Support Agreement, net of related guarantee fees	18	17
Total	1,498	1,871
Total	178	374
Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	24	11
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	295	297
Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	43	40
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270
Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	216	227
Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	519	537
Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	378	76
Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	12	273
Effect of netting and allocation of collateral	89	451
Derivative liabilities	13	191
Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	18	136
Effect of netting and allocation of collateral	82	18
Derivative liabilities	158	70
Effect of netting and allocation of collateral	(1)
Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1
Derivative liabilities	8	8
Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		105
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	339	330
Short-term investments held in Rabbi Trust	62	55
Support Agreement, net of related guarantee fees	0	0
Total	566	930
Total	1	0
Level 1 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	21	10
Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	291	293
Level 1 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	27	27
Level 1 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 1 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 1 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	27	27
Level 1 | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Level 1 | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Effect of netting and allocation of collateral	89	451
Derivative liabilities	0	0
Level 1 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	82
Effect of netting and allocation of collateral	76	12
Derivative liabilities	2	0
Effect of netting and allocation of collateral	(1)
Level 1 | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0
Derivative liabilities	0	0
Level 1 | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	499	515
Short-term investments held in Rabbi Trust	0	0
Support Agreement, net of related guarantee fees	0	0
Total	890	883
Total	177	374
Level 2 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	3	1
Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	4	4
Level 2 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	16	13
Level 2 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270
Level 2 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	216	227
Level 2 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	492	510
Level 2 | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	378	76
Level 2 | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	12	273
Effect of netting and allocation of collateral	0	0
Derivative liabilities	13	191
Level 2 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	19
Effect of netting and allocation of collateral	0	0
Derivative liabilities	156	70
Effect of netting and allocation of collateral	0
Level 2 | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1
Derivative liabilities	8	8
Level 2 | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		105
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Short-term investments held in Rabbi Trust	0	0
Support Agreement, net of related guarantee fees	18	17
Total	42	58
Total	0	0
Level 3 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 3 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 3 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 3 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 3 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Level 3 | Interest rate instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Level 3 | Commodity contracts not subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Effect of netting and allocation of collateral	0	0
Derivative liabilities	0	0
Level 3 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	18	35
Effect of netting and allocation of collateral	6	6
Derivative liabilities	0	0
Effect of netting and allocation of collateral	0
Level 3 | Foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0
Derivative liabilities	0	0
Level 3 | Interest rate and foreign exchange instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
San Diego Gas and Electric Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	838	845
Total	936	982
Total	1	1
San Diego Gas and Electric Company | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	24	11
San Diego Gas and Electric Company | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	295	297
San Diego Gas and Electric Company | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	43	40
San Diego Gas and Electric Company | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270
San Diego Gas and Electric Company | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	216	227
San Diego Gas and Electric Company | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	519	537
San Diego Gas and Electric Company | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	18	120
Effect of netting and allocation of collateral	80	17
Derivative liabilities	2	1
Effect of netting and allocation of collateral	(1)
San Diego Gas and Electric Company | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	339	330
Total	413	423
Total	1	0
San Diego Gas and Electric Company | Level 1 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	21	10
San Diego Gas and Electric Company | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	291	293
San Diego Gas and Electric Company | Level 1 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	27	27
San Diego Gas and Electric Company | Level 1 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 1 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 1 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	27	27
San Diego Gas and Electric Company | Level 1 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	82
Effect of netting and allocation of collateral	74	11
Derivative liabilities	2	0
Effect of netting and allocation of collateral	(1)
San Diego Gas and Electric Company | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	499	515
Total	499	518
Total	0	1
San Diego Gas and Electric Company | Level 2 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	3	1
San Diego Gas and Electric Company | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	4	4
San Diego Gas and Electric Company | Level 2 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	16	13
San Diego Gas and Electric Company | Level 2 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	260	270
San Diego Gas and Electric Company | Level 2 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	216	227
San Diego Gas and Electric Company | Level 2 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	492	510
San Diego Gas and Electric Company | Level 2 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	3
Effect of netting and allocation of collateral	0	0
Derivative liabilities	0	1
Effect of netting and allocation of collateral	0
San Diego Gas and Electric Company | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
Total	24	41
Total	0	0
San Diego Gas and Electric Company | Level 3 | Short-term investments, primarily cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 3 | Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 3 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 3 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 3 | Total debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nuclear decommissioning trusts	0	0
San Diego Gas and Electric Company | Level 3 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	18	35
Effect of netting and allocation of collateral	6	6
Derivative liabilities	0	0
Effect of netting and allocation of collateral	0
Southern California Gas Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2	17
Total	156	69
Southern California Gas Company | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		16
Effect of netting and allocation of collateral	2	1
Derivative liabilities	156	69
Southern California Gas Company | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2	1
Total	0	0
Southern California Gas Company | Level 1 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0
Effect of netting and allocation of collateral	2	1
Derivative liabilities	0	0
Southern California Gas Company | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	16
Total	156	69
Southern California Gas Company | Level 2 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		16
Effect of netting and allocation of collateral	0	0
Derivative liabilities	156	69
Southern California Gas Company | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Total	0	0
Southern California Gas Company | Level 3 | Commodity contracts subject to rate recovery
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0
Effect of netting and allocation of collateral	0	0
Derivative liabilities	$ 0	$ 0