DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE IMPACT ON THE INCOME (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings			$ (39,000,000)	$ 20,000,000
Fair Value Hedging [Member] | Interest Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedge ineffectiveness	$ 0	$ 0	0	0
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	1,000,000	1,000,000	3,000,000
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | Interest Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	1,000,000	3,000,000	5,000,000
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | Other Income, Net [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	0	(2,000,000)	(2,000,000)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	16,000,000	(138,000,000)	(238,000,000)	(139,000,000)
Pretax (loss) gain reclassified from AOCI into earnings	(12,000,000)	(5,000,000)	(23,000,000)	(13,000,000)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Expense [Member] | Interest rate and foreign exchange instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	(16,000,000)	(10,000,000)	(26,000,000)	(22,000,000)
Pretax (loss) gain reclassified from AOCI into earnings	(4,000,000)	(5,000,000)	(11,000,000)	(14,000,000)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Equity Earnings, Before Income Tax [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	17,000,000	(134,000,000)	(190,000,000)	(123,000,000)
Pretax (loss) gain reclassified from AOCI into earnings	(3,000,000)	(3,000,000)	(8,000,000)	(9,000,000)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Remeasurement of Equity Method Investment [Member] | Interest rate and foreign exchange instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	0	0	0	0
Pretax (loss) gain reclassified from AOCI into earnings	(7,000,000)	0	(7,000,000)	0
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Equity Earnings, Net of Income Tax [Member] | Interest rate and foreign exchange instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	13,000,000	0	(20,000,000)	0
Pretax (loss) gain reclassified from AOCI into earnings	2,000,000	0	(4,000,000)	0
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Revenues: Energy- Related Businesses [Member] | Commodity Contract Not Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	2,000,000	6,000,000	(2,000,000)	6,000,000
Pretax (loss) gain reclassified from AOCI into earnings	0	3,000,000	7,000,000	10,000,000
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	(125,000,000)	(15,000,000)	(137,000,000)	(78,000,000)
Not Designated as Hedging Instrument [Member] | Other Income, Net [Member] | Other foreign currency derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	(11,000,000)	(4,000,000)	(23,000,000)	(7,000,000)
Not Designated as Hedging Instrument [Member] | Equity Earnings, Net of Income Tax [Member] | Other foreign currency derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	1,000,000	(3,000,000)	3,000,000	(4,000,000)
Not Designated as Hedging Instrument [Member] | Revenues: Energy- Related Businesses [Member] | Commodity Contract Not Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	3,000,000	21,000,000	(26,000,000)	33,000,000
Not Designated as Hedging Instrument [Member] | Operation and Maintenance [Member] | Commodity Contract Not Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	(2,000,000)	1,000,000	(1,000,000)
Not Designated as Hedging Instrument [Member] | Cost of Electric Fuel and Purchased Power [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	(118,000,000)	(27,000,000)	(90,000,000)	(100,000,000)
Not Designated as Hedging Instrument [Member] | Cost of Natural Gas [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	0	(2,000,000)	1,000,000
San Diego Gas and Electric Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings			2,000,000	3,000,000
San Diego Gas and Electric Company [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	2,000,000	(4,000,000)	(5,000,000)	(9,000,000)
Pretax (loss) gain reclassified from AOCI into earnings	(3,000,000)	(3,000,000)	(9,000,000)	(9,000,000)
San Diego Gas and Electric Company [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	(118,000,000)	(28,000,000)	(90,000,000)	(101,000,000)
San Diego Gas and Electric Company [Member] | Not Designated as Hedging Instrument [Member] | Operation and Maintenance [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	(1,000,000)	0	(1,000,000)
San Diego Gas and Electric Company [Member] | Not Designated as Hedging Instrument [Member] | Cost of Electric Fuel and Purchased Power [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	(118,000,000)	(27,000,000)	(90,000,000)	(100,000,000)
Southern California Gas Company [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Expense [Member] | Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	0	0	0	0
Pretax (loss) gain reclassified from AOCI into earnings	(1,000,000)	0	(1,000,000)	0
Southern California Gas Company [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	(1,000,000)	(2,000,000)	1,000,000
Southern California Gas Company [Member] | Not Designated as Hedging Instrument [Member] | Operation and Maintenance [Member] | Commodity Contract Not Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	0	(1,000,000)	0	0
Southern California Gas Company [Member] | Not Designated as Hedging Instrument [Member] | Cost of Natural Gas [Member] | Commodity Contracts Subject To Rate Recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) on derivatives recognized in earnings	$ 0	$ 0	$ (2,000,000)	$ 1,000,000