COMMITMENTS AND CONTINGENCIES - OTHER LITIGATION (Details) £ in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)	Oct. 01, 2015 GBP (£)	Oct. 01, 2014 GBP (£)
Wind Farm [Member] | San Diego Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Estimated Tax Equity Investment	$ 285
Ratepayer Credit	$ 39
So Cal Gas PCB Litigation [Member] | Southern California Gas Company [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number Of Lawsuits	7
Number of Lawsuits Settled	6
Mobile Gas Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number Of Lawsuits	14
Number of Lawsuits Settled	11
Loss Contingency Lawsuits Remaining	3
Loss Contingency Number Of Plaintiffs	250
Outstanding Equity Agreed To Sell, Percentage	100.00%
HMRC VAT Claim [Member]
Loss Contingencies [Line Items]
VAT Tax Claim Paid Upon Appeal | £		£ 146	£ 86
Investment in RBS Sempra Commodities LLP	$ 67