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Contractual interest rate for funds borrowed, under the debt agreement.

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DEBT - Summary of Total Unsecured Notes Payable Outstanding (Details) - USD ($) $ in Thousands					6 Months Ended
	Jul. 17, 2019	Jun. 23, 2017	May 11, 2017	Jan. 18, 2017	Jun. 30, 2022	Dec. 31, 2021	Jan. 26, 2021	Mar. 01, 2018
Debt Instrument [Line Items]
Debt issuance costs, net					$ (2,268)	$ 0
Debt issuance costs, accumulated amortization					2,394	2,070
American Assets Trust, L.P. \| Forward Contracts
Debt Instrument [Line Items]
Loss on derivative settlement		$ 500
Gain on derivative settlement	$ 500		$ 700	$ 10,400
American Assets Trust, L.P. \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					1,550,000	1,550,000
Debt issuance costs, net					(11,481)	(11,762)
Total Debt Outstanding					1,538,519	1,538,238
Debt issuance costs, accumulated amortization					$ 10,925	9,462
American Assets Trust, L.P. \| Term Loan A \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative fixed interest rate (in percent)					2.70%
American Assets Trust, L.P. \| Term Loan A \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 100,000	100,000
Stated Maturity Date					Jan. 05, 2027
American Assets Trust, L.P. \| Term Loan B \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative fixed interest rate (in percent)					3.15%			2.65%
American Assets Trust, L.P. \| Term Loan B \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 100,000	100,000
Stated Maturity Date					Mar. 01, 2023
American Assets Trust, L.P. \| Term Loan C \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative fixed interest rate (in percent)					3.14%			2.64%
American Assets Trust, L.P. \| Term Loan C \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 50,000	50,000
Stated Maturity Date					Mar. 01, 2023
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series F \| Forward Contracts
Debt Instrument [Line Items]
Effective rate of debt instrument (in percent)					3.85%
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series F \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 100,000	100,000
Stated interest rate					3.78%
Stated Maturity Date					Jul. 19, 2024
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series B \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 100,000	100,000
Stated interest rate					4.45%
Stated Maturity Date					Feb. 02, 2025
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series C \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 100,000	100,000
Stated interest rate					4.50%
Stated Maturity Date					Apr. 01, 2025
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series D \| Forward Contracts
Debt Instrument [Line Items]
Effective rate of debt instrument (in percent)					3.87%
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series D \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 250,000	250,000
Stated interest rate					4.29%
Stated Maturity Date					Mar. 01, 2027
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series E \| Forward Contracts
Debt Instrument [Line Items]
Effective rate of debt instrument (in percent)					4.18%
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series E \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 100,000	100,000
Stated interest rate					4.24%
Stated Maturity Date					May 23, 2029
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series G \| Forward Contracts
Debt Instrument [Line Items]
Effective rate of debt instrument (in percent)					3.88%
American Assets Trust, L.P. \| Senior Guaranteed Notes, Series G \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 150,000	150,000
Stated interest rate					3.91%
Stated Maturity Date					Jul. 30, 2030
American Assets Trust, L.P. \| 3.375% Senior Unsecured Notes
Debt Instrument [Line Items]
Stated interest rate							3.375%
American Assets Trust, L.P. \| 3.375% Senior Unsecured Notes \| Unsecured term loans, net
Debt Instrument [Line Items]
Long-term debt, principal balance					$ 500,000	$ 500,000
Stated interest rate					3.38%
Stated Maturity Date					Feb. 01, 2031