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v3.25.1

SHORT-TERM AND LONG-TERM DEBT - Narrative (Details) - USD ($) | 3 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Mar. 31, 2025 | Apr. 30, 2025 | Mar. 26, 2025 | Mar. 03, 2025 | Dec. 31, 2024
CL&P |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Notes payable to Eversource parent | $ 0 |  |  |  | $ 280,000,000
CL&P | Related Party |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Notes payable to Eversource parent |  |  |  |  | 280,000,000.0
PSNH |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Notes payable to Eversource parent | 114,500,000 |  |  |  | 131,100,000
PSNH | Related Party |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Notes payable to Eversource parent | 114,500,000 |  |  |  | 131,100,000
NSTAR Gas Series R First Mortgage Bonds | NSTAR Gas Series Y First Mortgage Bonds | First Mortgage | Subsequent Event |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Face amount |  | $ 205,000,000.0 |  |  |
NSTAR Gas Series R First Mortgage Bonds | NSTAR Gas Series Z First Mortgage Bonds | First Mortgage | Subsequent Event |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Face amount |  | $ 20,000,000.0 |  |  |
Line of Credit | CL&P |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity | 375,000,000 |  |  |  |
Amount outstanding under line of credit | 0 |  |  |  | 0
Line of Credit | PSNH |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity | 250,000,000 |  |  | $ 300,000,000 |
Amount outstanding under line of credit | 0 |  |  |  | 0
Line of Credit | Yankee Gas |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity |  |  | $ 360,000,000 |  |
Commercial Paper | NSTAR Electric |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity | 650,000,000 |  |  |  |
Line of Credit | NSTAR Electric |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity | 650,000,000 |  |  |  |
Eversource Parent | Commercial Paper |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity | 2,000,000,000.00 |  |  |  |
Eversource Parent | Line of Credit |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Maximum borrowing capacity | $ 2,000,000,000 |  |  |  |
Debt instrument term (in years) | 5 years |  |  |  |
NSTAR Electric | Line of Credit | NSTAR Electric |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Debt instrument term (in years) | 5 years |  |  |  |
NSTAR Electric and Eversource | Line of Credit |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |
Amount outstanding under line of credit | $ 0 |  |  |  | $ 0

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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
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