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Environmental Matters - Additional Information (Detail) - USD ($) $ in Millions | 1 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Oct. 31, 2023 | Jun. 30, 2024 | Dec. 31, 2022
Site Contingency [Line Items] |  |  |
Amortization period for environmental costs |  | 5 years |
Remediation costs |  |  | $ 5.6
Environmental Restoration Costs |  |  |
Site Contingency [Line Items] |  |  |
Estimated Costs Accrued For Remediation |  |  | $ 2.5
Fitchburg Manufactured Gas Plant Site [Member] |  |  |
Site Contingency [Line Items] |  |  |
Estimated Costs Accrued For Remediation | $ 40,000.0 |  |
Remediation costs | $ 3.5 |  |

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