Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Common Shares
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	490,000,000	490,000,000
Common stock, shares outstanding (in shares)	46,431,341	45,732,109
Common stock, shares issued (in shares)	46,431,341	45,732,109
American Assets Trust, L.P.
Limited partners' capital, units issued (in shares)	17,888,822	17,888,822
Limited partners' capital, units outstanding (in shares)	17,888,822	17,888,822
General partners' capital, units issued (in shares)	46,431,341	45,732,109
General partners' capital, units outstanding (in shares)	46,431,341	45,732,109