XML 110 R82.htm IDEA: XBRL DOCUMENT
v3.25.0.1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) | 12 Months Ended
--- | ---
Dec. 31, 2024 USD ($) project regulatedUtility customer | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
Summary of Accounting Policies [Line Items] |  |  |
Number of electric and natural gas customers | customer | 4,600,000 |  |
Number of offshore wind projects | project | 3 |  |
Goodwill | $ 3,571,333,000 | $ 4,532,100,000 | $ 4,522,600,000
Charitable contributions | $ 0 | 20,000,000 | $ 8,000,000.0
Offshore Wind Business |  |  |
Summary of Accounting Policies [Line Items] |  |  |
Ownership interest (in percent) | 50.00% |  |
Tax Equity |  |  |
Summary of Accounting Policies [Line Items] |  |  |
Ownership interest (in percent) | 50.00% |  |
Energy Relief Fund |  |  |
Summary of Accounting Policies [Line Items] |  |  |
Restricted cash, current | $ 20,000,000 | 20,000,000 |
Restricted cash, noncurrent | $ 5,900,000 | 14,100,000 |
CL&P |  |  |
Summary of Accounting Policies [Line Items] |  |  |
Period of accounts receivable recoverable under financial or medical duress | 180 days |  |
Maximum loans receivable outstanding | $ 70,000,000 |  |
Loans transferred receivable current | 9,400,000 | 8,500,000 |
Loans transferred receivable non-current | $ 17,300,000 | $ 14,500,000 |
Yankee Gas Services Company |  |  |
Summary of Accounting Policies [Line Items] |  |  |
Period of accounts receivable recoverable under financial or medical duress | 90 days |  |
Connecticut, Massachusetts and New Hampshire |  |  |
Summary of Accounting Policies [Line Items] |  |  |
Number of regulated utilities | regulatedUtility | 12 |  |

X
- Definition Maximum Loans Receivable Outstanding + References No definition available. + Details
Name: | es_MaximumLoansReceivableOutstanding
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number Of Offshore Wind Projects + References No definition available. + Details
Name: | es_NumberOfOffshoreWindProjects
Namespace Prefix: | es_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Electric, Natural Gas And Water Customers + References No definition available. + Details
Name: | es_NumberofElectricNaturalGasAndWaterCustomers
Namespace Prefix: | es_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Regulated Utilities + References No definition available. + Details
Name: | es_NumberofRegulatedUtilities
Namespace Prefix: | es_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Payments For Charitable Contributions, Related Parties + References No definition available. + Details
Name: | es_PaymentsForCharitableContributionsRelatedParties
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Period of Accounts Receivable Recoverable Under Financial or Medical Duress + References No definition available. + Details
Name: | es_PeriodofAccountsReceivableRecoverableUnderFinancialorMedicalDuress
Namespace Prefix: | es_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition [Line Items] for Summary of Accounting Policies [Table] + References No definition available. + Details
Name: | es_SummaryofAccountingPoliciesLineItems
Namespace Prefix: | es_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 49 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-49 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482548/350-20-55-24 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 852 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481372/852-10-55-10 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(15)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482598/350-20-45-1 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(10)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost, after allowance for credit loss, of financing receivable classified as current. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 + Details
Name: | us-gaap_NotesAndLoansReceivableNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of financing receivable, classified as noncurrent. + References No definition available. + Details
Name: | us-gaap_NotesAndLoansReceivableNetNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-8 + Details
Name: | us-gaap_RestrictedCashCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(17)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 45 -Paragraph 5 -SubTopic 210 -Topic 954 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477220/954-210-45-5 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-8 + Details
Name: | us-gaap_RestrictedCashNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=es_OffshoreWindBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=es_TaxEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=es_EnergyReliefFundMerrimackValleyProgramsMember
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: | dei_LegalEntityAxis=es_YankeeGasServicesCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=es_ConnecticutMassachusettsandNewHampshireMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |