SEGMENT REPORTING - Net Real Estate and Secured Note Payable Balances for Each Segment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net real estate	$ 2,734,556	$ 2,681,981
Secured Notes Payable	75,000	111,000
Capital Expenditures	121,155	107,730
Office
Segment Reporting Information [Line Items]
Net real estate	1,615,479	1,536,212
Secured Notes Payable	75,000	111,000
Capital Expenditures	102,443	93,116
Retail
Segment Reporting Information [Line Items]
Net real estate	579,219	591,107
Secured Notes Payable	0	0
Capital Expenditures	12,177	7,232
Multifamily
Segment Reporting Information [Line Items]
Net real estate	370,993	381,315
Capital Expenditures	4,889	5,841
Mixed-Use
Segment Reporting Information [Line Items]
Net real estate	168,865	173,347
Capital Expenditures	1,646	1,541
American Assets Trust, L.P.
Segment Reporting Information [Line Items]
Net real estate	2,734,556	2,681,981
Secured notes payable \| American Assets Trust, L.P.
Segment Reporting Information [Line Items]
Debt issuance costs	$ 422	$ 35

Capital Expenditures And Leasing Commissions

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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- Definition

Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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