GENERAL INFORMATION AND OTHER FINANCIAL DATA - TRANSACTIONS WITH AFFILIATES (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	$ 15	$ 13	[1]
Total due to unconsolidated affiliates – noncurrent	(355)	(352)	[1]
Related Party
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	15	13
Total due to unconsolidated affiliates – noncurrent	(355)	(352)
Various affiliates
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	4	5
Tax Sharing Arrangement | Related Party
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	11	8
SDG&E | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(67)	(59)	[2]
SDG&E | Various affiliates
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(14)	(3)
SDG&E | Due to/from Sempra Energy
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(44)	(42)
Income taxes due (to) from Sempra	21	38
SDG&E | Due to/from SoCalGas
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(9)	(14)
SoCalGas
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	34	16	[1]
SoCalGas | Related Party
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	34	16
Total due to unconsolidated affiliates – current	(25)	(38)	[1]
SoCalGas | Various affiliates
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	2	2
SoCalGas | Due to/from Sempra Energy
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – current	(25)	(38)
Income taxes due (to) from Sempra	(78)	(6)
SoCalGas | Due to/from SDG&E
Related Party Transaction [Line Items]
Total due from unconsolidated affiliates – current	32	14
5.5% Note due January 14, 2026 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ 0	(8)
Stated rate of debt (as a percent)	5.50%
5.5% Note due July 14, 2026 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ 0	(12)
Stated rate of debt (as a percent)	5.50%
5.5% Note due January 19, 2027 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ 0	(15)
Stated rate of debt (as a percent)	5.50%
5.5% Note due July 21, 2027 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ (9)	(19)
Stated rate of debt (as a percent)	5.50%
5.5% Note due January 19, 2028 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ (48)	(48)
Stated rate of debt (as a percent)	5.50%
5.5% Note due July 18, 2028 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ (42)	(41)
Stated rate of debt (as a percent)	5.50%
5.5% Note due January 22, 2029 | TAG Pipeline | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ (44)	0
Stated rate of debt (as a percent)	5.50%
5.74% Note due December 17, 2029 | TAG JV Norte | Related Party
Related Party Transaction [Line Items]
Total due to unconsolidated affiliates – noncurrent	$ (212)	$ (209)
Stated rate of debt (as a percent)	5.74%

[1] Derived from audited financial statements.

[2] Derived from audited financial statements.