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Environmental Matters - Additional Information (Detail) $ in Millions | 9 Months Ended
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Sep. 30, 2022 USD ($)
Environmental Restoration Costs |
Site Contingency [Line Items] |
Estimated Costs Accrued For Remediation | $ 0.8
Maine | Environmental Restoration Costs |
Site Contingency [Line Items] |
Amortization period for environmental costs | 5 years
New Hampshire |
Site Contingency [Line Items] |
Amortization period for environmental costs | 7 years

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