Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2014	Dec. 31, 2013
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	490,000,000	490,000,000
Common stock, shares outstanding	43,701,669	40,512,563
American Assets Trust, L.P.
Limited Partners' Capital Account, Units Issued	17,905,257	17,917,109
Limited Partners' Capital Account, Units Outstanding	17,905,257	17,917,109
General Partners' Capital Account, Units Issued	43,701,669	40,512,563
General Partners' Capital Account, Units Outstanding	43,701,669	40,512,563