Debt Summary of Total Secured Notes Payable Outstanding (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Notes payable, total		$ 1,034,002
American Assets Trust, L.P. | The Shops at Kalakaua
Debt Instrument [Line Items]
Stated Interest Rate	[1],[2]	0.00%
Stated Maturity Date	[1],[2]	May 01, 2015
American Assets Trust, L.P. | The Land Mark at One Market
Debt Instrument [Line Items]
Stated Interest Rate	[1],[3]	0.00%
Stated Maturity Date	[1],[3]	Jul. 05, 2015
American Assets Trust, L.P. | Del Monte Center
Debt Instrument [Line Items]
Stated Interest Rate	[1],[4]	0.00%
Stated Maturity Date	[1],[4]	Jul. 08, 2015
American Assets Trust, L.P. | First & Main
Debt Instrument [Line Items]
Stated Interest Rate	[1]	3.97%
Stated Maturity Date	[1]	Jul. 01, 2016
American Assets Trust, L.P. | Imperial Beach Gardens
Debt Instrument [Line Items]
Stated Interest Rate	[1]	6.16%
Stated Maturity Date	[1]	Sep. 01, 2016
American Assets Trust, L.P. | Mariner's Point
Debt Instrument [Line Items]
Stated Interest Rate	[1]	6.09%
Stated Maturity Date	[1]	Sep. 01, 2016
American Assets Trust, L.P. | South Bay Marketplace
Debt Instrument [Line Items]
Stated Interest Rate	[1]	5.48%
Stated Maturity Date	[1]	Feb. 10, 2017
American Assets Trust, L.P. | Waikiki Beach Walk - Retail
Debt Instrument [Line Items]
Stated Interest Rate	[1]	5.39%
Stated Maturity Date	[1]	Jul. 01, 2017
American Assets Trust, L.P. | Solana Beach Corporate Centre III-IV
Debt Instrument [Line Items]
Stated Interest Rate	[5]	6.39%
Stated Maturity Date	[5]	Aug. 01, 2017
American Assets Trust, L.P. | Loma Palisades
Debt Instrument [Line Items]
Stated Interest Rate	[1]	6.09%
Stated Maturity Date	[1]	Jul. 01, 2018
American Assets Trust, L.P. | One Beach Street
Debt Instrument [Line Items]
Stated Interest Rate	[1]	3.94%
Stated Maturity Date	[1]	Apr. 01, 2019
American Assets Trust, L.P. | Torrey Reserve - North Court
Debt Instrument [Line Items]
Stated Interest Rate	[5]	7.22%
Stated Maturity Date	[5]	Jun. 01, 2019
American Assets Trust, L.P. | Torrey Reserve-VCI, VCII, VCIII
Debt Instrument [Line Items]
Stated Interest Rate	[5]	6.36%
Stated Maturity Date	[5]	Jun. 01, 2020
American Assets Trust, L.P. | Solana Beach Corporate Centre I-II
Debt Instrument [Line Items]
Stated Interest Rate	[5]	5.91%
Stated Maturity Date	[5]	Jun. 01, 2020
American Assets Trust, L.P. | Solana Beach Towne Centre
Debt Instrument [Line Items]
Stated Interest Rate	[5]	5.91%
Stated Maturity Date	[5]	Jun. 01, 2020
American Assets Trust, L.P. | City Center Bellevue
Debt Instrument [Line Items]
Stated Interest Rate	[1]	3.98%
Stated Maturity Date	[1]	Nov. 01, 2022
Secured notes payable | American Assets Trust, L.P.
Debt Instrument [Line Items]
Secured notes payable, Principal Balance		$ 584,002	$ 819,983
Unamortized fair value adjustment		(4,259)	(7,172)
Notes payable, total		$ 579,743	812,811
Number of year amortization schedule		30 years
Secured notes payable | American Assets Trust, L.P. | The Shops at Kalakaua
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1],[2]	$ 0	19,000
Secured notes payable | American Assets Trust, L.P. | The Land Mark at One Market
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1],[3]	0	133,000
Secured notes payable | American Assets Trust, L.P. | Del Monte Center
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1],[4]	0	82,300
Secured notes payable | American Assets Trust, L.P. | First & Main
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	84,500	84,500
Secured notes payable | American Assets Trust, L.P. | Imperial Beach Gardens
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	20,000	20,000
Secured notes payable | American Assets Trust, L.P. | Mariner's Point
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	7,700	7,700
Secured notes payable | American Assets Trust, L.P. | South Bay Marketplace
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	23,000	23,000
Secured notes payable | American Assets Trust, L.P. | Waikiki Beach Walk - Retail
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	130,310	130,310
Secured notes payable | American Assets Trust, L.P. | Solana Beach Corporate Centre III-IV
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[5]	35,920	36,376
Secured notes payable | American Assets Trust, L.P. | Loma Palisades
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	73,744	73,744
Secured notes payable | American Assets Trust, L.P. | One Beach Street
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	21,900	21,900
Secured notes payable | American Assets Trust, L.P. | Torrey Reserve - North Court
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[5]	20,749	21,075
Secured notes payable | American Assets Trust, L.P. | Torrey Reserve-VCI, VCII, VCIII
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[5]	6,995	7,101
Secured notes payable | American Assets Trust, L.P. | Solana Beach Corporate Centre I-II
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[5]	11,119	11,302
Secured notes payable | American Assets Trust, L.P. | Solana Beach Towne Centre
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[5]	37,065	37,675
Secured notes payable | American Assets Trust, L.P. | City Center Bellevue
Debt Instrument [Line Items]
Secured notes payable, Principal Balance	[1]	$ 111,000	$ 111,000

[1] Interest only.

[2] Loan repaid in full, without premium or penalty, on February 2, 2015.

[3] Loan repaid in full, without premium or penalty, on April 6, 2015.

[4] Loan repaid in full, without premium or penalty, on February 6, 2015.

[5] Principal payments based on a 30-year amortization schedule.