DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE IMPACT ON THE INCOME (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	$ 106,000,000	$ (4,000,000)	[1]
Fair Value Hedging [Member] | Interest Expense [Member] | Interest rate instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedge ineffectiveness		0
Cash Flow Hedging [Member] | Interest Expense [Member] | Interest rate instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedge ineffectiveness	0	0
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | Interest Expense [Member] | Interest rate instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings		2,000,000
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	(4,000,000)	(165,000,000)
Pretax gain (loss) reclassified from AOCI into earnings	(12,000,000)	(1,000,000)
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	(11,000,000)
Pretax gain (loss) reclassified from AOCI into earnings	3,000,000	(4,000,000)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Equity Earnings, Before Income Tax [Member] | Interest rate instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	(5,000,000)	(137,000,000)
Pretax gain (loss) reclassified from AOCI into earnings	(2,000,000)	(3,000,000)
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	(9,000,000)	(18,000,000)
Pretax gain (loss) reclassified from AOCI into earnings	(2,000,000)	(1,000,000)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Revenues: Energy- Related Businesses [Member] | Foreign exchange instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	(9,000,000)	0
Pretax gain (loss) reclassified from AOCI into earnings	(2,000,000)	0
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Revenues: Energy- Related Businesses [Member] | Commodity contracts not subject to rate recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	3,000,000	1,000,000
Pretax gain (loss) reclassified from AOCI into earnings	(9,000,000)	7,000,000
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	49,000,000	(9,000,000)
Not Designated as Hedging Instrument [Member] | Other Income, Net [Member] | Foreign exchange instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	65,000,000	3,000,000
Not Designated as Hedging Instrument [Member] | Equity Earnings, Net of Income Tax [Member] | Foreign exchange instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	0	2,000,000
Not Designated as Hedging Instrument [Member] | Revenues: Energy- Related Businesses [Member] | Commodity contracts not subject to rate recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	14,000,000	(1,000,000)
Not Designated as Hedging Instrument [Member] | Operation and Maintenance [Member] | Commodity contracts not subject to rate recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	(1,000,000)	0
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 on derivatives recognized in earnings	(29,000,000)	(12,000,000)
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 on derivatives recognized in earnings	0	(1,000,000)
San Diego Gas and Electric Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	0	1,000,000	[1]
San Diego Gas and Electric Company [Member] | Cash Flow Hedging [Member] | Interest Expense [Member] | Interest rate instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedge ineffectiveness	0	0
San Diego Gas and Electric Company [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Interest Expense [Member] | Interest rate instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain (loss) recognized in OCI	0	(5,000,000)
Pretax gain (loss) reclassified from AOCI into earnings	(3,000,000)	(3,000,000)
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 on derivatives recognized in earnings	(29,000,000)	(12,000,000)
Southern California Gas Company [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	(1,000,000)	(1,000,000)
Southern California Gas Company [Member] | Not Designated as Hedging Instrument [Member] | Operation and Maintenance [Member] | Commodity contracts not subject to rate recovery [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gain on derivatives recognized in earnings	(1,000,000)	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 on derivatives recognized in earnings	$ 0	$ (1,000,000)

[1] As adjusted for the adoption of ASU 2016-09 as of January 1, 2016.