v3.26.1
Environmental Commitments and Contingencies - Additional Information (Detail)
3 Months Ended
Mar. 31, 2026
USD ($)
site
Dec. 31, 2025
USD ($)
Environmental Commitments And Contingencies [Line Items]    
Company's exposure in number of former Manufactured Gas Plant Sites | site 7  
Environmental liabilities $ 3,000,000.0 $ 2,900,000
Seaford [Member] | Minimum [Member]    
Environmental Commitments And Contingencies [Line Items]    
Estimated costs of remediation range, minimum 300,000  
Seaford [Member] | Maximum [Member]    
Environmental Commitments And Contingencies [Line Items]    
Estimated costs of remediation range, minimum 800,000  
Manufactured Gas Plant [Member]    
Environmental Commitments And Contingencies [Line Items]    
Regulatory Assets for future recovery of environmental costs 200,000  
FPU [Member]    
Environmental Commitments And Contingencies [Line Items]    
Environmental liabilities $ 3,300,000 $ 3,100,000