OTHER FINANCIAL DATA - INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense	$ 167	$ (106)	[1]	$ 462	$ 2	[1]
Effective income tax rate	40.00%	95.00%		39.00%	1.00%
Income tax expense from transactional effects of foreign currency and inflation	$ 52			$ 149
Income tax expense from transactional effects of foreign currency and inflation net of noncontrolling interest	34			99
Gain (loss) from foreign currency derivatives	32			97
Gain (loss) from foreign currency derivatives after-tax	19			58
San Diego Gas and Electric Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense	$ 54	$ 48		$ 144	$ 113	[1]
Effective income tax rate	26.00%	36.00%		32.00%	34.00%
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense	$ 19	$ (29)		$ 117	$ 54	[1]
Effective income tax rate	24.00%	100.00%		31.00%	21.00%

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