SUPPLEMENTAL FINANCIAL INFORMATION Supplemental Cash Flows (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Interest paid (net of interest capitalized)				$ 117	$ 103
Income tax refunds received				0	1
Additions to property, plant and equipment and other long-lived assets	[1]			96	107
Allowance for equity funds used during construction		$ 6	$ 8	12	16
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability				$ 0	$ 3

[1] Amounts consist of current and accrued liabilities for construction, labor, materials and other costs that have not been included in investing activities. These amounts have not been paid for as of June 30, 2020 or 2019, respectively, but will be or have been included as a cash outflow from investing activities for expenditures for property, plant and equipment when paid.