DEBT - Summary of Total Secured Notes Payable Outstanding (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Debt issuance costs, net	$ (2,430)	$ 0
Debt issuance costs, accumulated amortization	2,232	2,070
American Assets Trust, L.P. | Secured notes payable, net
Debt Instrument [Line Items]
Long-term debt, principal balance	111,000	111,000
Debt issuance costs, net	(24)	(35)
Total Debt Outstanding	110,976	110,965
Debt issuance costs, accumulated amortization	397	387
American Assets Trust, L.P. | City Center Bellevue | Secured notes payable, net
Debt Instrument [Line Items]
Long-term debt, principal balance	$ 111,000	$ 111,000
Stated Interest Rate	3.98%