DEBT - Summary of Total Secured Notes Payable Outstanding (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Debt discount and issuance costs, net of accumulated amortization of $5,703 and $11,709, respectively	$ (1,782)	$ 0
Debt issuance costs, accumulated amortization	415	0
American Assets Trust, L.P. | Secured notes payable, net
Debt Instrument [Line Items]
Principal Balance as of	75,000	75,000
Debt discount and issuance costs, net of accumulated amortization of $5,703 and $11,709, respectively	(399)	(422)
Total Unsecured Notes Payable	74,601	74,578
Debt issuance costs, accumulated amortization	474	452
American Assets Trust, L.P. | 5.08% City Center Bellevue, October 2027 | Secured notes payable, net
Debt Instrument [Line Items]
Principal Balance as of	$ 75,000	$ 75,000
Stated interest rate	5.08%