v3.26.3
Regulatory Matters - Regulatory Assets, Net (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Regulatory assets:    
Total regulatory assets $ 269,353 $ 254,862
Less: current portion of regulatory assets 14,621 8,315
Total regulatory assets, less current portion 254,732 246,547
Regulatory liabilities:    
Total regulatory liabilities 583,599 546,797
Total regulatory liabilities, less current portion $ 583,599 546,797
Minimum    
Regulatory liabilities:    
Estimated service lives of assets 5 years  
Maximum    
Regulatory liabilities:    
Estimated service lives of assets 100 years  
Cost of removal    
Regulatory liabilities:    
Total regulatory liabilities $ 417,924 394,391
Future income tax benefits due to customers    
Regulatory liabilities:    
Total regulatory liabilities 80,921 82,285
Unrecognized pensions and other postretirement benefits    
Regulatory liabilities:    
Total regulatory liabilities 30,942 32,996
Per- and Polyfluoroalkyl substances (“PFAS”) legal settlement proceeds    
Regulatory liabilities:    
Total regulatory liabilities 36,388 24,682
Employee benefit costs    
Regulatory liabilities:    
Total regulatory liabilities 13,296 8,771
Water supply costs    
Regulatory liabilities:    
Total regulatory liabilities 437 0
Revenue adjustment mechanisms    
Regulatory liabilities:    
Total regulatory liabilities 1,238 0
Other    
Regulatory liabilities:    
Total regulatory liabilities 2,453 3,672
Future income tax benefits due to customers    
Regulatory assets:    
Total regulatory assets 222,606 204,384
Monterey Water Revenue Adjustment Mechanism (“M-WRAM”)    
Regulatory assets:    
Total regulatory assets 6,785 8,553
Business combinations debt premium    
Regulatory assets:    
Total regulatory assets 7,866 9,772
Employee benefit costs    
Regulatory assets:    
Total regulatory assets 6,429 5,823
Catastrophic event memorandum accounts (“CEMA”)    
Regulatory assets:    
Total regulatory assets 0 127
Revenue adjustment mechanisms    
Regulatory assets:    
Total regulatory assets 8,393 7,931
Customer Assistance Program ("CAP") balancing account    
Regulatory assets:    
Total regulatory assets 5,041 3,696
Water supply costs    
Regulatory assets:    
Total regulatory assets 0 847
Ground Water Regulation Legal Expenses memorandum account (“GWRLEMA”)    
Regulatory assets:    
Total regulatory assets 946 0
Other    
Regulatory assets:    
Total regulatory assets $ 11,287 $ 13,729