v2.4.0.6
Document and Entity Information
6 Months Ended
Jun. 30, 2012
Aug. 03, 2012
Document and Entity Information    
Entity Registrant Name AMERICAN STATES WATER CO  
Entity Central Index Key 0001056903  
Document Type 10-Q  
Document Period End Date Jun. 30, 2012  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   18,923,668
Document Fiscal Year Focus 2012  
Document Fiscal Period Focus Q2