INCOME TAXES (The Significant Components of Deferred Income Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Gross Deferred Income Tax Assets
Customer Advances and Contributions in Aid of Construction	$ 20	$ 19
Other Postretirement Benefits	15	15
Investment Tax Credit Carryforward	23	19
Income Taxes Payable Through Future Rates	67	74
Other	93	76
Total Gross Deferred Income Tax Assets	218	203
Gross Deferred Income Tax Liabilities
Plant, Net	(682)	(639)
PPFAC	(23)	(6)
Plant Abandonments	(8)	(11)
Pensions	(18)	(17)
Income Taxes Payable Through Future Rates	(4)	(7)
Other	(32)	(16)
Total Gross Deferred Income Tax Liabilities	(767)	(696)
Deferred Income Taxes, Net	$ (549)	$ (493)