PARTNERS' CAPITAL OF AMERICAN ASSETS TRUST, L.P. (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 shares	Sep. 30, 2022 shares	Sep. 30, 2023 shares	Sep. 30, 2022 shares
Capital Unit [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)	573,949	483,110	573,070	483,895
American Assets Trust, L.P.
Capital Unit [Line Items]
Percentage of ownership interests classified as noncontrolling	21.20%		21.20%
American Assets Trust, L.P.
Capital Unit [Line Items]
Noncontrolling common units (in shares)	16,181,537		16,181,537
American Assets Trust, L.P. | Operating Partnership Units
Capital Unit [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)	573,949	483,110	573,070	483,895
American Assets Trust, L.P. | Common Shares
Capital Unit [Line Items]
Conversion of operating partnership units (in shares)			0
American Assets Trust, L.P. | Limited Partners
Capital Unit [Line Items]
Common unit conversion ratio			1