FAIR VALUE MEASUREMENTS AND DERIVATIVE INSTRUMENTS (Financial Instruments Measured at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Assets
Cash equivalents	$ 15,000,000
Restricted cash	26,000,000	$ 35,000,000
Energy derivative contract assets - regulatory recovery	48,000,000	100,000,000
Energy derivative contract assets - no regulatory recovery	17,000,000	4,000,000
Total Assets	106,000,000	139,000,000
Liabilities
Energy derivative contract liabilities - regulatory recovery	(14,000,000)	(18,000,000)
Total Liabilities	(14,000,000)	(18,000,000)
Total Assets (Liabilities), Net	92,000,000	121,000,000
Level 1
Assets
Cash equivalents	15,000,000
Restricted cash	26,000,000	35,000,000
Energy derivative contract assets - regulatory recovery	0	0
Energy derivative contract assets - no regulatory recovery	0	0
Total Assets	41,000,000	35,000,000
Liabilities
Energy derivative contract liabilities - regulatory recovery	0	0
Total Liabilities	0	0
Total Assets (Liabilities), Net	41,000,000	35,000,000
Level 2
Assets
Cash equivalents	0
Restricted cash	0	0
Energy derivative contract assets - regulatory recovery	48,000,000	100,000,000
Energy derivative contract assets - no regulatory recovery	17,000,000	4,000,000
Total Assets	65,000,000	104,000,000
Liabilities
Energy derivative contract liabilities - regulatory recovery	(14,000,000)	(18,000,000)
Total Liabilities	(14,000,000)	(18,000,000)
Total Assets (Liabilities), Net	51,000,000	$ 86,000,000
Level 3
Liabilities
Total Assets (Liabilities), Net	$ 0