v3.26.3
RELATED PARTY TRANSACTIONS (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Related Party Transaction [Line Items]          
Accounts Payable $ 163,708   $ 163,708   $ 128,540
Operating Revenues 565,841 $ 544,515 1,337,227 $ 1,317,495  
Other 27,000 10,000 56,000 44,000  
Related Party          
Related Party Transaction [Line Items]          
Accounts Receivables 12,000   12,000   9,000
Accounts Payable 3,000   3,000   5,000
Related Party | Common Costs, UNS Energy Affiliates          
Related Party Transaction [Line Items]          
Common costs 7,000 7,000 21,000 19,000  
Related Party | Transmission Revenues, UNS Electric          
Related Party Transaction [Line Items]          
Operating Revenues 2,000 2,000 6,000 6,000  
Related Party | Control Area Services, UNS Electric          
Related Party Transaction [Line Items]          
Other 1,000 1,000 2,000 2,000  
Related Party | Wholesale Revenues, UNS Electric          
Related Party Transaction [Line Items]          
Operating Revenues 1,000 1,000 2,000 2,000  
Related Party | Corporate Services, UNS Energy          
Related Party Transaction [Line Items]          
Corporate services 2,000 1,000 $ 8,000 7,000  
Massachusetts formula - TEP's allocation (percentage)     84.00%    
Management fee 2,000 1,000 $ 7,000 6,000  
Related Party | Purchased Power, UNS Electric          
Related Party Transaction [Line Items]          
Purchased power 1,000 1,000 2,000 2,000  
Related Party | Corporate Services, UNS Energy Affiliates          
Related Party Transaction [Line Items]          
Corporate services 1,000 0 2,000 1,000  
Related Party | Capacity Charges , UNS Gas          
Related Party Transaction [Line Items]          
Capacity charges 0 $ 0 1,000 $ 1,000  
Related Party | UNS Electric          
Related Party Transaction [Line Items]          
Accounts Receivables 8,000   8,000   7,000
Accounts Payable 2,000   2,000   1,000
Related Party | UNS Gas          
Related Party Transaction [Line Items]          
Accounts Receivables 2,000   2,000   2,000
Related Party | UNS Energy          
Related Party Transaction [Line Items]          
Accounts Receivables 2,000   2,000   0
Accounts Payable $ 1,000   $ 1,000   $ 4,000