PARTNERS CAPITAL OF AMERICAN ASSETS TRUST, L.P. (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Partnership Units
Capital Unit [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)	169,963	168,529	171,760	196,927
Common Shares
Capital Unit [Line Items]
Conversion of operating partnership units (in shares)			10,694
American Assets Trust, L.P.
Capital Unit [Line Items]
Noncontrolling common units (in shares)	17,888,822		17,888,822
Percentage of ownership interests classified as noncontrolling	28.20%		28.20%
American Assets Trust, L.P. | Operating Partnership Units
Capital Unit [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)	169,963	168,529	171,760	196,927
American Assets Trust, L.P. | Common Shares
Capital Unit [Line Items]
Conversion of operating partnership units (in shares)			10,694