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COMMITMENTS AND CONTINGENCIES - Guarantees and Obligations Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 14, 2022	Nov. 30, 2022	Jun. 14, 2022
Line of Credit \| PSNH
Loss Contingencies [Line Items]
Amount of long-term debt requested for issuance		$ 600.0
Line of Credit \| CL&P
Loss Contingencies [Line Items]
Amount of long-term debt requested for issuance			$ 1,150.0
Line of Credit \| NSTAR Gas
Loss Contingencies [Line Items]
Amount of long-term debt requested for issuance				$ 325.0
Sunrise Wind LLC \| Forecast \| Subsequent Event
Loss Contingencies [Line Items]
Maximum exposure	$ 58.1