REAL ESTATE - Operating Results for Acquisition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Real Estate [Line Items]
Revenues	$ 112,491	$ 111,198	$ 109,721	$ 107,754	$ 106,000	$ 111,023	$ 104,155	$ 101,470	$ 441,164	$ 422,648	$ 375,828
Operating expenses									319,417	307,914	275,959
OPERATING INCOME	29,399	31,139	31,492	29,716	27,073	31,003	28,316	28,342	$ 121,747	114,734	$ 99,869
Net income attributable to American Assets Trust, Inc.	$ 10,481	$ 11,778	$ 11,983	$ 16,136	$ 9,629	$ 12,772	$ 10,582	$ 10,523
Bel-Spring 520
Real Estate [Line Items]
Revenues										2,512
Operating expenses										2,417
OPERATING INCOME										95
Net income attributable to American Assets Trust, Inc.										$ 95