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v3.23.3

SHORT-TERM AND LONG-TERM DEBT - Summary of Long-Term Debt Issuance and Repayments (Details) - USD ($) $ in Thousands | 1 Months Ended | 9 Months Ended
--- | --- | ---
Nov. 30, 2023 | Sep. 30, 2023 | Aug. 31, 2023 | Jul. 31, 2023 | May 31, 2023 | Mar. 31, 2023 | Jan. 31, 2023 | Sep. 30, 2023 | Sep. 30, 2022
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Retirement of Long-Term Debt |  |  |  |  |  |  |  | $ (1,203,000) | $ (775,000)
CL&P |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Retirement of Long-Term Debt |  |  |  |  |  |  |  | $ (400,000) | $ 0
CL&P | First Mortgage | CL&P 2023 Series A First Mortgage Bonds |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  |  |  | 5.25% |  |
Issuances |  |  |  |  |  |  | $ 500,000 |  |
CL&P | First Mortgage | CL&P 2013 Series A First Mortgage Bonds |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  |  |  | 2.50% |  |
Retirement of Long-Term Debt |  |  |  |  |  |  | $ (400,000) |  |
CL&P | First Mortgage | CL&P 2023 Series B First Mortgage Bonds |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  | 4.90% |  |  |  |  |
Issuances |  |  |  | $ 300,000 |  |  |  |  |
PSNH | First Mortgage | PSNH Series W First Mortgage Bonds |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  |  |  | 5.15% |  |
Issuances |  |  |  |  |  |  | $ 300,000 |  |
PSNH | First Mortgage | PSNH Series X First Mortgage Bonds |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  | 5.35% |  |  |  |  |  | 5.35% |
Issuances |  | $ 300,000 |  |  |  |  |  |  |
PSNH | First Mortgage | PSNH Series S First Mortgage Bonds | Subsequent Event | Forecast |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) | 3.50% |  |  |  |  |  |  |  |
Retirement of Long-Term Debt | $ (325,000) |  |  |  |  |  |  |  |
Yankee Gas | First Mortgage | Yankee Gas Series V First Mortgage Bonds |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  | 5.51% |  |  |  |  |  |
Issuances |  |  | $ 170,000 |  |  |  |  |  |
Aquarion Water Company Of Connecticut | Senior Notes | Aquarion Water Company of Connecticut Senior Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  | 5.89% |  |  |  |  |  | 5.89% |
Issuances |  | $ 50,000 |  |  |  |  |  |  |
NSTAR Electric | Debentures | NSTAR Electric 2023 Debentures |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  | 5.60% |  |  |  |  |  | 5.60% |
Issuances |  | $ 150,000 |  |  |  |  |  |  |
Eversource Parent | Senior Notes | Eversource Parent Series Z Senior Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  | 5.45% | 5.45% |  |  |
Issuances |  |  |  |  | $ 550,000 | $ 750,000 |  |  |
Eversource Parent | Senior Notes | Eversource Parent Series F Senior Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  | 2.80% |  |  |  |
Retirement of Long-Term Debt |  |  |  |  | $ (450,000) |  |  |  |
Eversource Parent | Senior Notes | Eversource Parent Series AA Senior Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  | 4.75% |  |  |  |
Issuances |  |  |  |  | $ 450,000 |  |  |  |
Eversource Parent | Senior Notes | Eversource Parent Series BB Senior Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Interest rate, stated percentage (in percent) |  |  |  |  | 5.125% |  |  |  |
Issuances |  |  |  |  | $ 800,000 |  |  |  |
Eversource Parent | Senior Notes | Eversource Parent Variable Rate Series T Senior Notes |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Retirement of Long-Term Debt |  |  | $ (350,000) |  |  |  |  |  |
Eversource Parent | Senior Notes | Eversource Parent Variable Rate Series T Senior Notes | Secured Overnight Financing Rate (SOFR) |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Basis spread on variable rate (in percent) |  |  | 0.25% |  |  |  |  |  |

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