Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
ASSETS
Operating real estate	$ 1,994,925	$ 1,931,698
Construction in progress	229,212	195,736
Held for development	9,423	9,390
Total Real estate, at cost	2,233,560	2,136,824
Accumulated depreciation	(396,464)	(361,424)
Net real estate	1,837,096	1,775,400
Cash and cash equivalents	40,158	59,357
Restricted cash	25,208	10,994
Accounts receivable, net	8,151	6,727
Deferred rent receivables, net	37,714	35,883
Other assets, net	47,748	53,401
TOTAL ASSETS	1,996,075	1,941,762
LIABILITIES AND EQUITY
Secured notes payable	579,449	812,811
Unsecured notes payable	450,000	250,000
Unsecured line of credit	25,000	0
Accounts payable and accrued expenses	50,806	50,861
Security deposits payable	5,781	5,521
Other liabilities and deferred credits, net	52,526	55,993
Total liabilities	$ 1,163,562	$ 1,175,186
Commitments and contingencies (Note 12)
American Assets Trust, Inc. stockholders’ equity
Common stock, $0.01 par value, 490,000,000 shares authorized, 45,349,121 and 43,701,669 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	$ 454	$ 437
Additional paid-in capital	863,515	795,065
Accumulated dividends in excess of net income	(60,976)	(60,291)
Accumulated other comprehensive (loss) income	(1,030)	92
Total American Assets Trust, Inc. stockholders’ equity	801,963	735,303
Noncontrolling interests	30,550	31,273
Total equity	832,513	766,576
Partners' Capital [Abstract]
TOTAL LIABILITIES AND EQUITY	1,996,075	1,941,762
American Assets Trust, L.P.
ASSETS
Operating real estate	1,994,925	1,931,698
Construction in progress	229,212	195,736
Held for development	9,423	9,390
Total Real estate, at cost	2,233,560	2,136,824
Accumulated depreciation	(396,464)	(361,424)
Net real estate	1,837,096	1,775,400
Cash and cash equivalents	40,158	59,357
Restricted cash	25,208	10,994
Accounts receivable, net	8,151	6,727
Deferred rent receivables, net	37,714	35,883
Other assets, net	47,748	53,401
TOTAL ASSETS	1,996,075	1,941,762
LIABILITIES AND EQUITY
Secured notes payable	579,449	812,811
Unsecured notes payable	450,000	250,000
Unsecured line of credit	25,000	0
Accounts payable and accrued expenses	50,806	50,861
Security deposits payable	5,781	5,521
Other liabilities and deferred credits, net	52,526	55,993
Total liabilities	$ 1,163,562	$ 1,175,186
Commitments and contingencies (Note 12)
American Assets Trust, Inc. stockholders’ equity
Accumulated other comprehensive (loss) income	$ (1,437)	$ 130
Partners' Capital [Abstract]
Limited partners' capital, 17,899,516 and 17,905,257 units issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	30,957	31,235
General partner's capital, 45,349,121 and 43,701,669 units issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	802,993	735,211
Total capital	832,513	766,576
TOTAL LIABILITIES AND EQUITY	$ 1,996,075	$ 1,941,762