DERIVATIVE INSTRUMENTS - Unobservable Inputs Utilized (Details) - Forward Reserve Prices - CL&P - Level 3 - $ / KWmo	Dec. 31, 2022	Dec. 31, 2021
Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input	0.44	0.50
Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input	0.50	1.15
Average
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative measurement input	0.47	0.82