INVESTMENTS IN UNCONSOLIDATED ENTITIES - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended	7 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Schedule of Equity Method Investments [Line Items]
Net income / Earnings	$ 153	$ 281
Oncor Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Operating revenues	1,095	2,352
Operating expense	(748)	(1,663)
Income from operations	347	689
Interest expense	(89)	(198)
Income tax expense	(53)	(105)
Net income / Earnings	191	351
Noncontrolling interest held by TTI	$ (38)	$ (70)