v3.26.1
Contingencies (Details)
$ in Millions
1 Months Ended 6 Months Ended
Sep. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
Party
Loss Contingencies [Line Items]    
Number of potentially responsible parties | Party   100
Investigation-related costs   $ 115
Undiscounted estimated total cost   1,700
Long-term operation and maintenance costs   500
lower range of costs   2,500
upper range of costs   5,500
Estimated low end of share of liability   20
EPA Investigation of Portland Harbor [Member]    
Loss Contingencies [Line Items]    
Remediation construction costs   $ 1,200
Loss from Catastrophes [Member]    
Loss Contingencies [Line Items]    
Remediation construction costs $ 375