v3.26.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NATURAL GAS IN STORAGE (Details)
$ in Thousands
Jun. 30, 2026
USD ($)
Bcf
Sep. 30, 2025
USD ($)
Bcf
Inventory [Line Items]    
Natural Gas in Storage, value | $ $ 152,941 $ 215,836
Natural Gas in Storage, Bcf | Bcf 34.8 44.3
NJNG    
Inventory [Line Items]    
Natural Gas in Storage, value | $ $ 118,286 $ 184,099
Natural Gas in Storage, Bcf | Bcf 20.2 30.8
ES    
Inventory [Line Items]    
Natural Gas in Storage, value | $ $ 32,912 $ 30,686
Natural Gas in Storage, Bcf | Bcf 14.1 13.2
S&T    
Inventory [Line Items]    
Natural Gas in Storage, value | $ $ 1,743 $ 1,051
Natural Gas in Storage, Bcf | Bcf 0.5 0.3