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Environmental Matters - Additional Information (Detail) | 3 Months Ended
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Mar. 31, 2025 USD ($)
Site Contingency [Line Items] |
Environmental Remediation Expense, before Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration] | Costs and Expenses
Environmental Restoration Costs |
Site Contingency [Line Items] |
Estimated Costs Accrued For Remediation | $ 5,600,000
Fitchburg Manufactured Gas Plant Site [Member] |
Site Contingency [Line Items] |
Environmental Remediation Expense, before Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration] | Costs and Expenses
remediation costs | $ 3,500,000
Fitchburg Manufactured Gas Plant Site [Member] | Environmental Restoration Costs |
Site Contingency [Line Items] |
Estimated Costs Accrued For Remediation | $ 40,000

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