DEBT - Summary of Total Secured Notes Payable Outstanding (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Notes payable, total	$ 1,700,000
Secured notes payable
Debt Instrument [Line Items]
Debt issuance costs, accumulated amortization	542	$ 452
American Assets Trust, L.P. | Secured notes payable
Debt Instrument [Line Items]
Principal Balance as of	75,000	75,000
Debt issuance costs, net of accumulated amortization of $542 and $452, respectively	(331)	(422)
Notes payable, total	74,669	74,578
American Assets Trust, L.P. | 5.08% City Center Bellevue, October 2027 | Secured notes payable
Debt Instrument [Line Items]
Principal Balance as of	$ 75,000	$ 75,000
Stated interest rate	5.08%