XML 100 R78.htm IDEA: XBRL DOCUMENT
v3.24.3

SHORT-TERM AND LONG-TERM DEBT - Narrative (Details) - USD ($) | 9 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2024 | Aug. 12, 2024 | Jul. 24, 2024 | May 01, 2024 | Feb. 08, 2024 | Dec. 31, 2023
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt | $ 25,971,408,000 |  |  |  |  | $ 23,588,616,000
NSTAR Electric |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt | 5,093,701,000 |  |  |  |  | 4,496,947,000
CL&P |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt | 5,110,791,000 |  |  |  |  | 4,814,429,000
Notes payable to Eversource parent | 135,000,000 |  |  |  |  | 249,670,000
CL&P | Related Party |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt |  |  |  |  |  | 207,300,000
Notes payable to Eversource parent | 135,000,000.0 |  |  |  |  | 457,000,000.0
PSNH |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt | 1,731,764,000 |  |  |  |  | 1,431,591,000
Notes payable to Eversource parent | 89,300,000 |  |  |  |  | 233,000,000
PSNH | Related Party |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Notes payable to Eversource parent | 89,300,000 |  |  |  |  | 233,000,000.0
Line of Credit | NSTAR Electric |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Maximum borrowing capacity |  |  |  | $ 2,400,000,000 |  |
Line of Credit | CL&P |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Maximum borrowing capacity | 375,000,000 |  | $ 1,000,000,000 |  |  |
Amount outstanding under line of credit | 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 |  |  |  |  |
Line of Credit | Eversource Gas Company of Massachusetts |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Maximum borrowing capacity |  | $ 325,000,000 |  |  |  |
Commercial Paper | NSTAR Electric |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Maximum borrowing capacity | 650,000,000 |  |  |  |  |
Commercial Paper | CL&P |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt |  |  |  |  |  | 207,300,000
Commercial Paper | Eversource Gas Company of Massachusetts |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Long-Term Debt | 100,000,000 |  |  |  |  |
Line of Credit |  |  |  |  |  |
Line of Credit Facility [Line Items] |  |  |  |  |  |
Amount outstanding under line of credit | 0 |  |  |  |  | $ 0
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 |  |  |  |  |

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_LineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481544/470-10-50-6 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481544/470-10-50-6 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(f)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 + Details
Name: | us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt classified as noncurrent. Excludes lease obligation. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_LongTermDebtNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Sum of the carrying values as of the balance sheet date of the portions of long-term notes payable due within one year or the operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(20)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_NotesPayableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=es_NstarElectricCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=es_TheConnecticutLightAndPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=es_PublicServiceCompanyOfNewHampshirePSNHMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=es_EversourceGasCompanyOfMassachusettsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShortTermDebtTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShortTermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=es_NstarElectricCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |