Consolidated Statement of Partners' Capital (Unaudited) - LP - USD ($) $ in Thousands		Total	Interest Expense	Early Extinguishment of Debt	American Assets Trust, L.P.	American Assets Trust, L.P. Interest Expense	American Assets Trust, L.P. Early Extinguishment of Debt	American Assets Trust, L.P. Accumulated Other Comprehensive Income (Loss)	American Assets Trust, L.P. Accumulated Other Comprehensive Income (Loss) Interest Expense	American Assets Trust, L.P. Accumulated Other Comprehensive Income (Loss) Early Extinguishment of Debt	American Assets Trust, L.P. Limited Partner	[1]	American Assets Trust, L.P. General Partner
Beginning partners' capital account (shares) at Dec. 31, 2020											16,181,537		60,476,292	[2]
Beginning partners' capital account at Dec. 31, 2020					$ 1,253,406			$ 2,737			$ (19,020)		$ 1,269,689	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		$ 1,733			1,733						339		$ 1,394	[2]
Forfeiture of restricted units (shares)	[2]												(4,006)
Distributions					(21,463)						$ (4,531)		$ (16,932)	[2]
Stock-based compensation					1,484								$ 1,484	[2]
Other comprehensive income - change in value of interest rate swaps		747			747			747
Reclassification of amortization of forward-starting swap realized gain			$ (275)	$ (193)		$ (275)	$ (193)		$ (275)	$ (193)
Ending partners' capital account (shares) at Mar. 31, 2021											16,181,537		60,472,286	[2]
Ending partners' capital account at Mar. 31, 2021					1,235,439			3,016			$ (23,212)		$ 1,255,635	[2]
Beginning partners' capital account (shares) at Dec. 31, 2020											16,181,537		60,476,292	[2]
Beginning partners' capital account at Dec. 31, 2020					1,253,406			2,737			$ (19,020)		$ 1,269,689	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		26,115			26,115
Other comprehensive income - change in value of interest rate swaps		1,657			1,657
Reclassification of amortization of forward-starting swap realized gain			(824)	(193)		(824)	(193)
Ending partners' capital account (shares) at Sep. 30, 2021											16,181,537		60,472,065	[2]
Ending partners' capital account at Sep. 30, 2021					1,218,691			3,377			$ (27,477)		$ 1,242,791	[2]
Beginning partners' capital account (shares) at Mar. 31, 2021											16,181,537		60,472,286	[2]
Beginning partners' capital account at Mar. 31, 2021					1,235,439			3,016			$ (23,212)		$ 1,255,635	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		11,487			11,487						2,411		$ 9,076	[2]
Issuance of restricted stock (shares)	[2]												5,184
Forfeiture of restricted units (shares)	[2]												(2,604)
Distributions					(21,464)						$ (4,531)		$ (16,933)	[2]
Stock-based compensation					1,484								$ 1,484	[2]
Other comprehensive income - change in value of interest rate swaps		475			475			475
Reclassification of amortization of forward-starting swap realized gain		(275)				(275)			(275)
Ending partners' capital account (shares) at Jun. 30, 2021											16,181,537		60,474,866	[2]
Ending partners' capital account at Jun. 30, 2021					1,227,146			3,216			$ (25,332)		$ 1,249,262	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		12,895			12,895						2,709		$ 10,186	[2]
Forfeiture of restricted units (shares)	[2]												(2,801)
Distributions					(22,995)						$ (4,854)		$ (18,141)	[2]
Stock-based compensation					1,484								$ 1,484	[2]
Other comprehensive income - change in value of interest rate swaps		435			435			435
Reclassification of amortization of forward-starting swap realized gain			(274)	0		(274)	0		(274)
Ending partners' capital account (shares) at Sep. 30, 2021											16,181,537		60,472,065	[2]
Ending partners' capital account at Sep. 30, 2021					1,218,691			3,377			$ (27,477)		$ 1,242,791	[2]
Beginning partners' capital account (shares) at Dec. 31, 2021											16,181,537		60,525,580	[2]
Beginning partners' capital account at Dec. 31, 2021					1,210,123			4,169			$ (30,138)		$ 1,236,092	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		13,514			13,514						2,836		$ 10,678	[2]
Forfeiture of restricted units (shares)	[2]												(3,121)
Distributions					(24,545)						$ (5,178)		$ (19,367)	[2]
Stock-based compensation					1,489								$ 1,489	[2]
Units withheld for employee taxes (shares)	[2]												(416)
Units withheld for employee taxes		(15)			(15)								$ (15)	[2]
Other comprehensive income - change in value of interest rate swaps		5,596			5,596			5,596
Reclassification of amortization of forward-starting swap realized gain			(275)			(275)			(275)
Ending partners' capital account (shares) at Mar. 31, 2022											16,181,537		60,522,043	[2]
Ending partners' capital account at Mar. 31, 2022					1,205,887			9,490			$ (32,480)		$ 1,228,877	[2]
Beginning partners' capital account (shares) at Dec. 31, 2021											16,181,537		60,525,580	[2]
Beginning partners' capital account at Dec. 31, 2021					1,210,123			4,169			$ (30,138)		$ 1,236,092	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		43,471			43,471
Other comprehensive income - change in value of interest rate swaps		13,117			13,117
Reclassification of amortization of forward-starting swap realized gain			(825)	0		(825)	0
Ending partners' capital account (shares) at Sep. 30, 2022											16,181,537		60,528,115	[2]
Ending partners' capital account at Sep. 30, 2022					1,197,723			16,461			$ (36,542)		$ 1,217,804	[2]
Beginning partners' capital account (shares) at Mar. 31, 2022											16,181,537		60,522,043	[2]
Beginning partners' capital account at Mar. 31, 2022					1,205,887			9,490			$ (32,480)		$ 1,228,877	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		13,588			13,588						2,852		$ 10,736	[2]
Issuance of restricted stock (shares)	[2]												6,072
Distributions					(24,547)						$ (5,178)		$ (19,369)	[2]
Stock-based compensation					2,001								$ 2,001	[2]
Other comprehensive income - change in value of interest rate swaps		3,314			3,314			3,314
Reclassification of amortization of forward-starting swap realized gain			(275)			(275)			(275)
Ending partners' capital account (shares) at Jun. 30, 2022											16,181,537		60,528,115	[2]
Ending partners' capital account at Jun. 30, 2022					1,199,968			12,529			$ (34,806)		$ 1,222,245	[2]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		16,369			16,369						3,442		12,927	[2]
Distributions					(24,547)						$ (5,178)		(19,369)	[2]
Stock-based compensation					2,001								$ 2,001	[2]
Other comprehensive income - change in value of interest rate swaps		$ 4,207			4,207			4,207
Reclassification of amortization of forward-starting swap realized gain			$ (275)	$ 0		$ (275)	$ 0		$ (275)
Ending partners' capital account (shares) at Sep. 30, 2022											16,181,537		60,528,115	[2]
Ending partners' capital account at Sep. 30, 2022					$ 1,197,723			$ 16,461			$ (36,542)		$ 1,217,804	[2]

[1] Consists of limited partnership interests held by third parties.

[2] Consists of general partnership interests held by American Assets Trust, Inc.