XML 80 R61.htm IDEA: XBRL DOCUMENT
v3.23.3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) customer in Millions |  |  | 3 Months Ended | 6 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 23, 2023 USD ($) | May 25, 2023 USD ($) a project mile | Sep. 30, 2023 USD ($) project | Jun. 30, 2023 USD ($) | Mar. 31, 2023 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2023 USD ($) project | Sep. 30, 2023 USD ($) regulatedUtility project customer | Sep. 30, 2022 USD ($) | Dec. 31, 2022 USD ($) | Jun. 30, 2022 USD ($) | Dec. 31, 2021 USD ($)
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of electric, natural gas and water customers | customer |  |  |  |  |  |  |  | 4.4 |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | $ 542,700,000 | $ 532,400,000 |  | $ 457,600,000 | $ 542,700,000 | $ 542,700,000 | $ 457,600,000 | $ 486,300,000 | $ 457,800,000 | $ 417,400,000
Number of offshore wind projects | project |  | 3 | 3 |  |  |  | 3 | 3 |  |  |  |
Payments for investment |  |  |  |  |  |  |  | $ 887,365,000 | 617,588,000 |  |  |
Impairment charge |  |  | $ 0 | 401,000,000 |  | 0 |  | 401,000,000 | 0 |  |  |
After-tax impairment |  |  |  | 331,000,000 |  |  |  |  |  |  |  |
Valuation allowance |  |  |  | $ 40,000,000 |  |  |  |  |  |  |  |
Percent realized of investment tax credit |  |  |  | 0.10 |  |  |  |  |  |  |  |
Expected value of investment tax credit |  |  |  | $ 400,000,000 |  |  |  |  |  |  |  |
Energy Relief Fund - Merrimack Valley Programs |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Restricted cash, current |  |  | 20,000,000 |  |  |  | $ 20,000,000 | 20,000,000 |  | 20,000,000 |  |
Restricted cash, noncurrent |  |  | 14,300,000 |  |  |  | 14,300,000 | 14,300,000 |  | 15,900,000 |  |
COVID-19 |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | 50,900,000 |  |  |  | 50,900,000 | 50,900,000 |  | 50,900,000 |  |
CL&P |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | 276,300,000 | 262,800,000 |  | 198,600,000 | 276,300,000 | $ 276,300,000 | 198,600,000 | 225,300,000 | 192,700,000 | 181,300,000
Period of accounts receivable recoverable under financial or medical duress |  |  |  |  |  |  |  | 180 days |  |  |  |
CL&P | COVID-19 |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | 16,000,000 |  |  |  | 16,000,000 | $ 16,000,000 |  | 16,000,000 |  |
NSTAR Electric |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | 100,800,000 | 97,800,000 |  | 99,500,000 | 100,800,000 | 100,800,000 | 99,500,000 | 95,000,000.0 | 100,500,000 | 97,000,000.0
NSTAR Electric | COVID-19 |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | 4,100,000 |  |  |  | 4,100,000 | 4,100,000 |  | 4,100,000 |  |
PSNH |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | 12,400,000 | 12,700,000 |  | $ 28,800,000 | 12,400,000 | 12,400,000 | $ 28,800,000 | 29,200,000 | $ 27,300,000 | $ 24,300,000
PSNH | COVID-19 |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Allowance for uncollectible accounts for late fees and other receivable amounts |  |  | $ 0 |  |  |  | $ 0 | $ 0 |  | $ 0 |  |
Yankee Gas |  |  |  |  |  |  |  |  |  |  |  |
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 |  |  |  |
Offshore Wind Business |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest (percent) |  | 50.00% | 50.00% |  |  |  | 50.00% | 50.00% |  |  |  |
North East Offshore |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest (percent) |  |  | 50.00% |  |  |  | 50.00% | 50.00% |  |  |  |
Renewable Energy Investment Fund |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest (percent) |  |  | 90.00% |  |  |  | 90.00% | 90.00% |  |  |  |
Proceeds from sale of equity method investments |  |  |  | $ 23,600,000 | $ 123,400,000 |  |  | $ 147,000,000 |  |  |  |
Renewable Energy Investment Fund | Equity Method Investee |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Charitable contributions |  |  |  |  | $ 20,000,000 |  |  |  |  |  |  |
Uncommitted Lease Area |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest (percent) |  | 50.00% |  |  |  |  |  |  |  |  |  |
Number of miles off south coast of Massachusetts | mile |  | 25 |  |  |  |  |  |  |  |  |  |
Uncommitted area of developable acres (in acres) | a |  | 175,000 |  |  |  |  |  |  |  |  |  |
Payments for investment |  | $ 625,000,000 |  |  |  |  |  |  |  |  |  |
Tax Equity Capital Contribution Agreement |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Payments for investment | $ 528,000,000 |  |  |  |  |  |  |  |  |  |  |
South Fork Wind Holdings, LLC Class A shares |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest (percent) |  |  | 100.00% |  |  |  | 100.00% | 100.00% |  |  |  |
Sunrise Wind LLC |  |  |  |  |  |  |  |  |  |  |  |
Summary of Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest (percent) |  |  | 50.00% |  |  |  | 50.00% | 50.00% |  |  |  |
Expected cash flows from sale of investment |  |  |  |  |  |  | $ 450,000,000 |  |  |  |  |

X
- Definition Equity Method Investment, Other than Temporary Impairment, After Tax + References No definition available. + Details
Name: | es_EquityMethodInvestmentOtherThanTemporaryImpairmentAfterTax
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Expected Cash Flows From Sale Of Investment + References No definition available. + Details
Name: | es_ExpectedCashFlowsFromSaleOfInvestment
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Expected Investment Tax Credit + References No definition available. + Details
Name: | es_ExpectedInvestmentTaxCredit
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Investment Tax Credit, Percent Realized + References No definition available. + Details
Name: | es_InvestmentTaxCreditPercentRealized
Namespace Prefix: | es_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

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 Miles Off South Coast Of Massachusetts + References No definition available. + Details
Name: | es_NumberOfMilesOffSouthCoastOfMassachusetts
Namespace Prefix: | es_
Data Type: | xbrli:integerItemType
Balance Type: | na
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 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 + References No definition available. + Details
Name: | es_PaymentsForCharitableContributions
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 Amount of allowance for credit loss on accounts receivable. + References Reference 1: 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)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-4 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481664/323-10-45-1 + Details
Name: | us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 Area of land subject to a ground lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147478964/842-20-50-3 + Details
Name: | us-gaap_LandSubjectToGroundLeases
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:areaItemType
Balance Type: | na
Period Type: | instant

X
- Definition The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 + Details
Name: | us-gaap_OperatingLossCarryforwardsValuationAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-13 + Details
Name: | us-gaap_PaymentsToAcquireEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-12 + Details
Name: | us-gaap_ProceedsFromSaleOfEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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//1943274/2147480632/954-210-45-5 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_CounterpartyNameAxis=es_EnergyReliefFundMerrimackValleyProgramsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnusualOrInfrequentItemAxis=es_COVID19Member
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_NstarElectricCompanyMember
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: | 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: |

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

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

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

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

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

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

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

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