FAIR VALUE MEASUREMENTS AND DERIVATIVE INSTRUMENTS (Financial Instruments Measured at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Assets
Cash equivalents	$ 8,000,000
Restricted cash	32,000,000	$ 34,000,000
Energy derivative contract assets - regulatory recovery	32,000,000	32,000,000
Energy derivative contract assets - no regulatory recovery	29,000,000	3,000,000
Total Assets	101,000,000	69,000,000
Liabilities
Energy derivative contract liabilities - regulatory recovery	(47,000,000)	(30,000,000)
Total Liabilities	(47,000,000)	(30,000,000)
Total Assets (Liabilities), Net	54,000,000	39,000,000
Level 1
Assets
Cash equivalents	8,000,000
Restricted cash	32,000,000	34,000,000
Energy derivative contract assets - regulatory recovery	0	0
Energy derivative contract assets - no regulatory recovery	0	0
Total Assets	40,000,000	34,000,000
Liabilities
Energy derivative contract liabilities - regulatory recovery	0	0
Total Liabilities	0	0
Total Assets (Liabilities), Net	40,000,000	34,000,000
Level 2
Assets
Cash equivalents	0
Restricted cash	0	0
Energy derivative contract assets - regulatory recovery	32,000,000	32,000,000
Energy derivative contract assets - no regulatory recovery	29,000,000	3,000,000
Total Assets	61,000,000	35,000,000
Liabilities
Energy derivative contract liabilities - regulatory recovery	(47,000,000)	(30,000,000)
Total Liabilities	(47,000,000)	(30,000,000)
Total Assets (Liabilities), Net	14,000,000	$ 5,000,000
Level 3
Liabilities
Total Assets (Liabilities), Net	$ 0