v3.26.1
Lines of Credit and Long-Term Liabilities (Details) - USD ($)
$ in Thousands
6 Months Ended
May 14, 2026
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Debt Instrument [Line Items]        
Weighted-average interest rate on short-term   4.71%   4.75%
Long-term borrowings   $ 16,938 $ 0  
Long-term debt, less current portion   1,881,479   $ 1,866,819
Current portion of long-term debt   8,648   $ 23,504
Senior Notes | SJWC        
Debt Instrument [Line Items]        
Long-term borrowings $ 70,000      
Senior Notes | SJWC | 5.83% Senior Note, Series R        
Debt Instrument [Line Items]        
Aggregate principal amount $ 55,000      
Interest rate percentage 5.83%      
Senior Notes | SJWC | 5.91% Senior Note, Series S        
Debt Instrument [Line Items]        
Aggregate principal amount $ 15,000      
Interest rate percentage 5.91%      
Revolving Credit Facility | Line of Credit        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity   367,700    
Standby Letters of Credit | Line of Credit        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity   $ 900