Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	490,000,000	490,000,000
Common stock, shares outstanding	45,407,719	43,701,669
American Assets Trust, L.P.
Limited Partners' Capital Account, Units Issued	17,899,516	17,905,257
Limited Partners' Capital Account, Units Outstanding	17,899,516	17,905,257
General Partners' Capital Account, Units Issued	45,407,719	43,701,669
General Partners' Capital Account, Units Outstanding	45,407,719	43,701,669
Common Stock
Common stock, shares issued	45,407,719	43,701,669