XML 172 R137.htm IDEA: XBRL DOCUMENT
v3.22.0.1

INCOME TAXES - Tax Credits and Loss Carryforwards (Details) - State and Local Jurisdiction - USD ($) $ in Millions | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Operating Loss Carryforwards [Line Items] |  |
Federal and State Tax Credit | $ 197.7 | $ 186.6
Operating Loss Carryforwards | 138.3 | 183.4
Federal and State Charitable Contribution | 23.7 | 10.2
The Connecticut Light and Power Company |  |
Operating Loss Carryforwards [Line Items] |  |
Federal and State Tax Credit | 137.0 | 133.4
Operating Loss Carryforwards | 0.0 | 0.0
Federal and State Charitable Contribution | 0.0 | 0.0
NSTAR Electric Company |  |
Operating Loss Carryforwards [Line Items] |  |
Federal and State Tax Credit | 0.0 | 0.0
Operating Loss Carryforwards | 0.0 | 0.0
Federal and State Charitable Contribution | 0.0 | 0.0
Public Service Company of New Hampshire |  |
Operating Loss Carryforwards [Line Items] |  |
Federal and State Tax Credit | 0.0 | 0.0
Operating Loss Carryforwards | 0.0 | 0.0
Federal and State Charitable Contribution | $ 0.0 | $ 0.0

X
- Definition Amount of future tax deductions arising from contributions in excess of statutory limitations in historical filings, and which can only be realized if sufficient tax-basis income is generated in future periods to enable deductions to be taken and providing tax laws continue to allow such deductions. + References No definition available. + Details
Name: | es_CharitableContribution
Namespace Prefix: | es_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 No definition available. + Details
Name: | us-gaap_OperatingLossCarryforwardsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319 + Details
Name: | us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
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: |