XML 41 R28.htm IDEA: XBRL DOCUMENT v3.19.1
Revenue from Contract with Customers - Additional Information (Details) - USD ($)
$ in Billions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Disaggregation of Revenue [Line Items]    
Revenue, remaining performance obligation $ 3.2  
ASUS | Contracted Services    
Disaggregation of Revenue [Line Items]    
Period of fixed price contracts to operate and maintain water systems at various military bases 50 years  
ASUS | Minimum    
Disaggregation of Revenue [Line Items]    
Revenue, remaining performance obligation, expected timing of satisfaction, explanation P36Y  
ASUS | Maximum    
Disaggregation of Revenue [Line Items]    
Revenue, remaining performance obligation, expected timing of satisfaction, explanation P49Y  
Sales | GOLDEN STATE WATER COMPANY | Water Service Utility Operations [Member]    
Disaggregation of Revenue [Line Items]    
Concentration Risk, Percentage 90.00% 90.00%
Sales | GOLDEN STATE WATER COMPANY | Electric Service Utility Operations    
Disaggregation of Revenue [Line Items]    
Concentration Risk, Percentage 85.00% 85.00%