Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Operating real estate	$ 2,244,865	$ 2,241,061
Construction in progress	54,346	50,498
Held for development	9,447	9,447
Total Real estate, at cost	2,308,658	2,301,006
Accumulated depreciation	(485,335)	(469,460)
Net real estate	1,823,323	1,831,546
Cash and cash equivalents	190,110	44,801
Restricted cash	9,836	9,950
Accounts receivable, net	7,558	9,330
Deferred rent receivables, net	38,555	38,452
Other assets, net	45,959	52,854
TOTAL ASSETS	2,115,341	1,986,933
LIABILITIES AND EQUITY
Secured notes payable, net	315,743	445,180
Unsecured notes payable, net	844,752	596,350
Unsecured line of credit	0	20,000
Accounts payable and accrued expenses	39,149	32,401
Security deposits payable	6,195	6,114
Other liabilities and deferred credits, net	47,793	48,337
Total liabilities	1,253,632	1,148,382
Commitments and contingencies (Note 11)
American Assets Trust, Inc. stockholders’ equity
Common stock, $0.01 par value, 490,000,000 shares authorized, 46,431,341 and 45,732,109 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	464	457
Additional paid-in capital	905,304	874,597
Accumulated dividends in excess of net income	(81,921)	(77,296)
Accumulated other comprehensive income	11,034	11,798
Total American Assets Trust, Inc. stockholders’ equity	834,881	809,556
Noncontrolling interests	26,828	28,995
Total equity	861,709	838,551
Partners' Capital [Abstract]
TOTAL LIABILITIES AND EQUITY	2,115,341	1,986,933
American Assets Trust, L.P.
ASSETS
Operating real estate	2,244,865	2,241,061
Construction in progress	54,346	50,498
Held for development	9,447	9,447
Total Real estate, at cost	2,308,658	2,301,006
Accumulated depreciation	(485,335)	(469,460)
Net real estate	1,823,323	1,831,546
Cash and cash equivalents	190,110	44,801
Restricted cash	9,836	9,950
Accounts receivable, net	7,558	9,330
Deferred rent receivables, net	38,555	38,452
Other assets, net	45,959	52,854
TOTAL ASSETS	2,115,341	1,986,933
LIABILITIES AND EQUITY
Secured notes payable, net	315,743	445,180
Unsecured notes payable, net	844,752	596,350
Unsecured line of credit	0	20,000
Accounts payable and accrued expenses	39,149	32,401
Security deposits payable	6,195	6,114
Other liabilities and deferred credits, net	47,793	48,337
Total liabilities	1,253,632	1,148,382
Commitments and contingencies (Note 11)
American Assets Trust, Inc. stockholders’ equity
Accumulated other comprehensive income	15,337	16,478
Partners' Capital [Abstract]
Limited partners' capital, 17,888,822 and 17,888,822 units issued and outstanding as of March 31, 2017 and December 31, 2016, respectively	22,525	24,315
General partner's capital, 46,431,341 and 45,732,109 units issued and outstanding as of March 31, 2017 and December 31, 2016, respectively	823,847	797,758
Total capital	861,709	838,551
TOTAL LIABILITIES AND EQUITY	$ 2,115,341	$ 1,986,933