v2.4.0.6
Document And Entity Information
3 Months Ended
Mar. 31, 2012
May 04, 2012
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2012  
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2012  
Entity Registrant Name American Assets Trust, Inc.  
Entity Central Index Key 0001500217  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   39,286,206