XML 63 R42.htm IDEA: XBRL DOCUMENT v3.25.0.1
Summary of Significant Accounting Policies - Property, Plant and Equipment and Intangible Assets (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Major components of depreciable plant and equipment [Abstract]      
Source of supply $ 228,621 $ 207,537  
Pumping plant 301,280 284,308  
Water treatment plant 367,836 354,617  
Transmission and distribution plant 3,015,978 2,820,358  
General plant 335,599 301,091  
Total depreciable plant and equipment $ 4,249,314 $ 3,967,911  
Useful Lives      
Depreciation expense as percentage of beginning of year balance of depreciable plant 2.90% 2.90% 3.30%
Capitalized interest costs $ 3,524 $ 2,900 $ 4,703
Equity funds capitalized 2,362 2,114 1,551
Water Plant      
Useful Lives      
Depreciation $ 111,575 $ 104,325 $ 99,413
Minimum      
Useful Lives      
Source of supply 20 years    
Pumping plant 5 years    
Water treatment plant 5 years    
Transmission and distribution plant 10 years    
General plant 5 years    
Useful life of intangible assets 5 years    
Maximum      
Useful Lives      
Source of supply 100 years    
Pumping plant 70 years    
Water treatment plant 62 years    
Transmission and distribution plant 100 years    
General plant 68 years    
Useful life of intangible assets 70 years