Consolidated Statement of Equity (Unaudited) - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands		Total	American Assets Trust, L.P.	American Assets Trust, L.P. Accumulated Other Comprehensive Income (Loss)	American Assets Trust, L.P. Limited Partner	[2]	American Assets Trust, L.P. General Partner		Swap American Assets Trust, L.P. Accumulated Other Comprehensive Income (Loss)	Common Shares	Additional Paid-in Capital	Accumulated Dividends in Excess of Net Income	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests - Unitholders in the Operating Partnership
Partners' Capital Account, Restricted Units Issued	[1]						4,900
Partners' Capital Account, Restricted Units Forfeiture	[1]						1,496
Beginning Balance (in shares) at Dec. 31, 2015										45,407,719
Beginning Balance at Dec. 31, 2015		$ 828,927								$ 454	$ 863,432	$ (64,066)	$ (258)	$ 29,365
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		21,371	$ 21,371		$ 6,035		$ 15,336	[1]				15,336		6,035
Issuance of restricted stock (in shares)										4,900
Issuance of restricted stock		0								$ 0	0
Forfeiture of restricted stock (in shares)										1,496
Forfeiture of restricted stock		0								$ 0	0
Dividends declared and paid		(31,653)										(22,703)		(8,950)
Stock-based compensation		1,255									1,255
Shares withheld for employee taxes (in shares)							(317)	[1]		(317)
Shares withheld for employee taxes		(12)	(12)				$ (12)	[1]		$ 0	(12)
Other comprehensive loss - change in value of interest rate swaps		(13,875)	(13,875)						$ (13,875)				(9,941)	(3,934)
Reclassification of amortization of forward-starting swap included in interest expense		(115)	(115)	$ (115)									(82)	(33)
Ending Balance (in shares) at Jun. 30, 2016										45,410,806
Ending Balance at Jun. 30, 2016		805,898								$ 454	864,675	(71,433)	(10,281)	22,483
Beginning partners' capital account (in shares) at Dec. 31, 2015					17,899,516		45,407,719	[1]
Beginning partners' capital account at Dec. 31, 2015			828,927	(339)	$ 29,446		$ 799,820	[1]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income		21,371	21,371		6,035		15,336	[1]				$ 15,336		6,035
Distributions			(31,653)		$ (8,950)		(22,703)	[1]
Stock-based compensation			1,255				$ 1,255	[1]
Shares withheld for employee taxes (in shares)							(317)	[1]		(317)
Shares withheld for employee taxes		(12)	(12)				$ (12)	[1]		$ 0	$ (12)
Other comprehensive income (loss) - unrealized gain (loss) on swap derivative during the period		(13,875)	(13,875)						$ (13,875)				(9,941)	(3,934)
Reclassification of amortization of forward-starting swap included in interest expense		$ (115)	(115)	(115)									$ (82)	$ (33)
Ending partners' capital account (in shares) at Jun. 30, 2016					17,899,516		45,410,806	[1]
Ending partners' capital account at Jun. 30, 2016			$ 805,898	$ (14,329)	$ 26,531		$ 793,696	[1]

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

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