OTHER FINANCIAL DATA - DUE TO DUE FROM AFFILIATES (Details) MXN in Billions	9 Months Ended	12 Months Ended
	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)		Sep. 30, 2017 MXN
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - current	$ 31,000,000	$ 26,000,000	[1]
Due from unconsolidated affiliates - noncurrent	506,000,000	201,000,000	[1]
Due to unconsolidated affiliates, current	$ (10,000,000)	(11,000,000)	[1]
Joint venture with PEMEX [Member] | LIBOR [Member]
Related Party Transaction [Line Items]
Spread on variable rate	450.00%
Interest rate on due from affiliate, noncurrent	5.73%
ESJ joint venture [Member] | LIBOR [Member]
Related Party Transaction [Line Items]
Spread on variable rate	637.50%
Interest rate on due from affiliate, noncurrent	7.61%
San Diego Gas and Electric Company [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - current	$ 1,000,000	4,000,000	[1]
Due to unconsolidated affiliates, current	(42,000,000)	(15,000,000)	[1]
Maximum borrowing capacity	750,000,000
San Diego Gas and Electric Company [Member] | Due to/from Other affiliates [Member]
Related Party Transaction [Line Items]
Due to unconsolidated affiliates, current	(7,000,000)	(7,000,000)
San Diego Gas and Electric Company [Member] | Due to/from Sempra Energy [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - current	0	3,000,000
Due to unconsolidated affiliates, current	(29,000,000)	0
Income taxes due from Sempra Energy	101,000,000	$ 159,000,000
Interest rate on due from affiliate, noncurrent		0.68%
Loan to unconsolidated affiliate, principal		$ 31,000,000
San Diego Gas and Electric Company [Member] | Due to/from Other Affiliates [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - current	1,000,000	1,000,000
San Diego Gas and Electric Company [Member] | Due to/from SoCalGas [Member]
Related Party Transaction [Line Items]
Due to unconsolidated affiliates, current	(6,000,000)	(8,000,000)
Southern California Gas Company [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - current	6,000,000	8,000,000	[1]
Due to unconsolidated affiliates, current	(35,000,000)	(28,000,000)	[1]
Maximum borrowing capacity	750,000,000
Southern California Gas Company [Member] | Due to/from Sempra Energy [Member]
Related Party Transaction [Line Items]
Due to unconsolidated affiliates, current	(35,000,000)	(28,000,000)
Income taxes due from Sempra Energy	10,000,000	5,000,000
Southern California Gas Company [Member] | Due to/from SDG&E [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - current	6,000,000	8,000,000
Sempra South American Utilities [Member] | Eletrans [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - noncurrent	$ 98,000,000	96,000,000
Interest rate on due from affiliate, noncurrent	4.00%
Sempra South American Utilities [Member] | Due to/from Other affiliates [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - noncurrent	$ 1,000,000	1,000,000
Sempra Mexico [Member] | IMG [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - noncurrent	307,000,000	0
Maximum borrowing capacity	$ 495,000,000			MXN 9.0
Sempra Mexico [Member] | IMG [Member] | Interbank Equilibrium Rate [Member]
Related Party Transaction [Line Items]
Spread on variable rate	220.00%
Interest rate on due from affiliate, noncurrent	9.58%
Sempra Mexico [Member] | Joint venture with PEMEX [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - noncurrent	$ 93,000,000	90,000,000
Sempra Mexico [Member] | ESJ joint venture [Member]
Related Party Transaction [Line Items]
Due from unconsolidated affiliates - noncurrent	$ 7,000,000	$ 14,000,000

[1] Derived from audited financial statements.