v3.26.1
SEGMENT INFORMATION - Narrative (Details)
$ in Millions
6 Months Ended
Jun. 30, 2026
USD ($)
reportableSegment
project
Segment Reporting [Line Items]  
Number of wind projects | project 3
Number of reportable segment 1
Yankee Gas, NSTAR Gas And EGMA  
Segment Reporting [Line Items]  
Natural gas transition service transaction costs | $ $ 77.7
CL&P  
Segment Reporting [Line Items]  
Number of reportable segment 1
NSTAR Electric  
Segment Reporting [Line Items]  
Number of reportable segment 1
PSNH  
Segment Reporting [Line Items]  
Number of reportable segment 1