ACQUISTION AND DIVESTITURE ACTIVITY - SUMMARY OF DECONSOLIDATIONS (Details) - USD ($) $ in Millions	1 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016		Sep. 12, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill			$ 2,397	$ 2,364	[1]		$ 819
Equity method investment			2,517	2,080
Sempra LNG & Midstream [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill			$ 0	$ 0			$ 72
Sempra LNG & Midstream [Member] | Energy South [Member] | Disposal Group Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds, net of transaction costs						$ 304
Cash						(2)
Other current assets						(17)
Property, plant and equipment, net						(199)
Goodwill						(72)
Other noncurrent assets						65
Other current liabilities						25
Long-term debt, including current portion						67
Other noncurrent liabilities						$ 89
Gain on sale of business and equity interests	$ 130	$ 130

[1] Reflects reclassifications to conform to current year presentation, which we discuss in Note 1.