v3.26.1
Regulation and Rates - Schedule of Power Cost Adjustment Mechanism (Details) - Subsidiaries
$ in Thousands
 6 Months Ended 9 Months Ended 12 Months Ended 15 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Dec. 31, 2026
USD ($)
Dec. 31, 2027
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2026
USD ($)
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount $ (39,639) $ 115,980     $ 97,700  
Annual Power Cost Variability, Interest 9 1,218        
Forecast            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount     $ 56,100 $ 59,500   $ 42,000
Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount (24,927) 35,976        
Annual Power Cost Variability, Interest 0 0        
Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount (14,712) 80,004        
Annual Power Cost Variability, Interest 9 1,218        
(Over) and under collected up to $17 million            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount (17,000) 17,000        
(Over) and under collected up to $17 million | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount (17,000) 17,000        
(Over) and under collected up to $17 million | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount $ 0 $ 0        
(Over) and under collected up to $17 million | Over | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 1 1        
(Over) and under collected up to $17 million | Over | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0 0        
(Over) and under collected up to $17 million | Under | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 1 1        
(Over) and under collected up to $17 million | Under | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0 0        
(Over) and under collected between $17 - $40 million            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount $ (22,648) $ 23,000        
(Over) and under collected between $17 - $40 million | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount (7,927) 11,500        
(Over) and under collected between $17 - $40 million | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount $ (14,721) $ 11,500        
(Over) and under collected between $17 - $40 million | Over | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.35 0.35        
(Over) and under collected between $17 - $40 million | Over | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.65 0.65        
(Over) and under collected between $17 - $40 million | Under | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.50 0.50        
(Over) and under collected between $17 - $40 million | Under | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.50 0.50        
(Over) or under collected beyond $40 million            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount $ 0 $ 74,762        
(Over) or under collected beyond $40 million | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount 0 7,476        
(Over) or under collected beyond $40 million | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability, Amount $ 0 $ 67,286        
(Over) or under collected beyond $40 million | Over | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.10 0.10        
(Over) or under collected beyond $40 million | Over | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.90 0.90        
(Over) or under collected beyond $40 million | Under | Company's Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.10 0.10        
(Over) or under collected beyond $40 million | Under | Customers' Share            
Schedule of Regulatory Assets and Liabiliaties [Line Items]            
Annual Power Cost Variability 0.90 0.90