v3.26.3
Commitments and Contingencies (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 32 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Loss Contingencies [Line Items]          
Proceeds from legal settlements         $ 36.2
SJWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements         24.4
CWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements         11.1
MWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements         0.7
Settlement payable to contract operators $ 0.5   $ 0.5   0.5
PFAS Contamination Legal Settlements          
Loss Contingencies [Line Items]          
Proceeds from legal settlements 0.1   11.1    
PFAS Contamination Legal Settlements | SJWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements     7.4    
PFAS Contamination Legal Settlements | CWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements     3.5    
PFAS Contamination Legal Settlements | MWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements     0.2    
Settlement payable to contract operators $ 0.1   $ 0.1   $ 0.1
3M Company PFAS Litigation Settlement          
Loss Contingencies [Line Items]          
Proceeds from legal settlements   $ 14.7   $ 21.2  
Receivable period for noncurrent cash proceeds receivable form legal settlement 7 years   7 years   7 years
Legal settlement receivable $ 5.6   $ 5.6   $ 5.6
3M Company PFAS Litigation Settlement | SJWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements   10.0   14.5  
3M Company PFAS Litigation Settlement | CWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements   4.6   6.5  
3M Company PFAS Litigation Settlement | MWC          
Loss Contingencies [Line Items]          
Proceeds from legal settlements   0.1   0.2  
Settlement payable to contract operators   $ 0.1   $ 0.1