FAIR VALUE MEASUREMENTS (Carrying Amount and Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Utility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt financial instrument	$ 3,138	$ 3,215
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt financial instrument	0	350
Carrying Amount | Utility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt financial instrument	1,500	17,450
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt financial instrument	0	350
Fair Value | Utility | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt financial instrument	1,503	$ 14,747
Fair value disclosure, pre-petition debt	$ 18,400