SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - TRANSACTIONS WITH AFFILIATES (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	$ 0	$ 13
Due to unconsolidated affiliates, noncurrent	0	(352)
Disposal Group Held-for-sale | SI Partners
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	3
Due to unconsolidated affiliates	477
Related Party
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	0	13
Total due to unconsolidated affiliates – current	(8)	0
Due to unconsolidated affiliates, noncurrent	0	(352)
Various affiliates
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	0	5
Tax Sharing Arrangement | Related Party
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	0	8
Total due to unconsolidated affiliates – current	(8)	0
SDG&E
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	1	0
SDG&E | Related Party
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	1	0
Total due to unconsolidated affiliates – current	(59)	(59)
SDG&E | Various affiliates
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	1	0
Total due to unconsolidated affiliates – current	(5)	(3)
SDG&E | Subsidiary of Common Parent
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(6)	(14)
SDG&E | Due to/from Sempra Energy
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(48)	(42)
Income taxes due from (to) Sempra	43	38
SoCalGas
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	8	16
SoCalGas | Related Party
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	8	16
Total due to unconsolidated affiliates – current	(35)	(38)
SoCalGas | Various affiliates
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	2	2
SoCalGas | Subsidiary of Common Parent
Related Party Transaction [Line Items]
Due from unconsolidated affiliates	6	14
SoCalGas | Due to/from Sempra Energy
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(35)	(38)
Income taxes due from (to) Sempra	$ (6)	(6)
5.5% Note due January 14, 2026 | TAG Pipelines Norte | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.50%
Due to unconsolidated affiliates, noncurrent	$ 0	(8)
5.5% Note due July 14, 2026 | TAG Pipelines Norte | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.50%
Due to unconsolidated affiliates, noncurrent	$ 0	(12)
5.5% Note due January 19, 2027 | TAG Pipelines Norte | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.50%
Due to unconsolidated affiliates, noncurrent	$ 0	(15)
5.5% Note due July 21, 2027 | TAG Pipelines Norte | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.50%
Due to unconsolidated affiliates, noncurrent	$ 0	(19)
5.5% Note due January 19, 2028 | TAG Pipelines Norte | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.50%
Due to unconsolidated affiliates, noncurrent	$ 0	(48)
5.5% Note due July 18, 2028 | TAG Pipelines Norte | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.50%
Due to unconsolidated affiliates, noncurrent	$ 0	(41)
5.74% Note due December 17, 2029 | TAG JV Notes | Related Party
Related Party Transaction [Line Items]
Stated rate of debt (as a percent)	5.74%
Due to unconsolidated affiliates, noncurrent	$ 0	$ (209)