v3.25.2
RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Summary of the Impact of Funding on the Income Statements (Details) - PSNH - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Condensed Income Statements, Captions [Line Items]        
Amortization of RRB Principal (included in Amortization of Regulatory Assets/(Liabilities), Net) $ (26,829) $ (28,729) $ (47,665) $ (49,993)
VIE | Rate Reduction Bonds        
Condensed Income Statements, Captions [Line Items]        
Amortization of RRB Principal (included in Amortization of Regulatory Assets/(Liabilities), Net) 10,800 10,800 21,600 21,600
Interest Expense on RRB Principal (included in Interest Expense) $ 3,300 $ 3,600 $ 6,600 $ 7,300