INVESTMENTS IN UNCONSOLIDATED ENTITIES - Summarized Financial Information (Details) $ in Millions	1 Months Ended
	Mar. 31, 2018 USD ($)
Schedule of Equity Method Investments [Line Items]
Net income / Earnings	$ 15
Oncor Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Gross revenues	236
Operating expense	(185)
Income from operations	51
Interest expense	(22)
Income tax expense	(7)
Net income / Earnings	$ 19