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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