Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Operating real estate	$ 2,226,437	$ 2,163,444
Construction in progress	52,139	73,121
Held for development	9,447	9,463
Total Real estate, at cost	2,288,023	2,246,028
Accumulated depreciation	(454,503)	(411,166)
Net real estate	1,833,520	1,834,862
Cash and cash equivalents	61,959	39,925
Restricted cash	10,246	11,623
Accounts receivable, net	8,604	7,518
Deferred rent receivables, net	38,283	38,422
Other assets, net	36,616	41,939
TOTAL ASSETS	1,989,228	1,974,289
LIABILITIES AND EQUITY
Secured notes payable, net	467,866	579,000
Unsecured notes payable, net	596,008	446,613
Unsecured line of credit	0	30,000
Accounts payable and accrued expenses	42,607	31,821
Security deposits payable	6,098	5,956
Other liabilities and deferred credits, net	62,137	51,972
Total liabilities	1,174,716	1,145,362
Commitments and contingencies (Note 11)
American Assets Trust, Inc. stockholders’ equity
Common stock, $0.01 par value, 490,000,000 shares authorized, 45,640,980 and 45,407,719 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	456	454
Additional paid-in capital	874,859	863,432
Accumulated dividends in excess of net income	(74,328)	(64,066)
Accumulated other comprehensive loss	(8,583)	(258)
Total American Assets Trust, Inc. stockholders’ equity	792,404	799,562
Noncontrolling interests	22,108	29,365
Total equity	814,512	828,927
Partners' Capital [Abstract]
TOTAL LIABILITIES AND EQUITY	1,989,228	1,974,289
American Assets Trust, L.P.
ASSETS
Operating real estate	2,226,437	2,163,444
Construction in progress	52,139	73,121
Held for development	9,447	9,463
Total Real estate, at cost	2,288,023	2,246,028
Accumulated depreciation	(454,503)	(411,166)
Net real estate	1,833,520	1,834,862
Cash and cash equivalents	61,959	39,925
Restricted cash	10,246	11,623
Accounts receivable, net	8,604	7,518
Deferred rent receivables, net	38,283	38,422
Other assets, net	36,616	41,939
TOTAL ASSETS	1,989,228	1,974,289
LIABILITIES AND EQUITY
Secured notes payable, net	467,866	579,000
Unsecured notes payable, net	596,008	446,613
Unsecured line of credit	0	30,000
Accounts payable and accrued expenses	42,607	31,821
Security deposits payable	6,098	5,956
Other liabilities and deferred credits, net	62,137	51,972
Total liabilities	1,174,716	1,145,362
Commitments and contingencies (Note 11)
American Assets Trust, Inc. stockholders’ equity
Accumulated other comprehensive loss	(11,955)	(339)
Partners' Capital [Abstract]
Limited partners' capital, 17,888,822 and 17,899,516 units issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	25,480	29,446
General partner's capital, 45,640,980 and 45,407,719 units issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	800,987	799,820
Total capital	814,512	828,927
TOTAL LIABILITIES AND EQUITY	$ 1,989,228	$ 1,974,289