Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
ASSETS
Operating real estate		$ 2,549,571	$ 2,536,474
Construction in progress		71,228	68,272
Held for development		9,392	9,392
Total Real estate, at cost		2,630,191	2,614,138
Accumulated depreciation		(590,338)	(537,431)
Net real estate		2,039,853	2,076,707
Cash and cash equivalents		47,956	82,610
Restricted cash		9,316	9,344
Accounts receivable, net		9,289	9,869
Deferred rent receivables, net		39,815	38,973
Other assets, net		52,021	42,361
TOTAL ASSETS		2,198,250	2,259,864
LIABILITIES AND EQUITY
Secured notes payable		182,572	279,550
Unsecured notes payable		1,045,863	1,045,470
Unsecured line of credit		62,337	0
Accounts payable and accrued expenses		46,616	38,069
Security deposits payable		8,844	6,570
Other liabilities and deferred credits		49,547	46,061
Total liabilities		1,395,779	1,415,720
Commitments and contingencies (Note 12)
American Assets Trust, Inc. stockholders' equity
Common stock, $0.01 par value, 490,000,000 shares authorized, 47,335,409 and 47,204,588 shares issued and outstanding at December 31, 2018 and December 31, 2017, respectively		474	473
Additional paid-in capital		920,661	919,066
Accumulated dividends in excess of net income		(128,778)	(97,280)
Accumulated other comprehensive income		10,620	11,451
Total American Assets Trust, Inc. stockholders' equity		802,977	833,710
Noncontrolling interests		(506)	10,434
Total equity		802,471	844,144
TOTAL LIABILITIES AND EQUITY		2,198,250	2,259,864
American Assets Trust, L.P.
ASSETS
Operating real estate		2,549,571	2,536,474
Construction in progress		71,228	68,272
Held for development		9,392	9,392
Total Real estate, at cost		2,630,191	2,614,138
Accumulated depreciation		(590,338)	(537,431)
Net real estate		2,039,853	2,076,707
Cash and cash equivalents		47,956	82,610
Restricted cash		9,316	9,344
Accounts receivable, net		9,289	9,869
Deferred rent receivables, net		39,815	38,973
Other assets, net		52,021	42,361
TOTAL ASSETS		2,198,250	2,259,864
LIABILITIES AND EQUITY
Secured notes payable		182,572	279,550
Unsecured notes payable		1,045,863	1,045,470
Unsecured line of credit		62,337	0
Accounts payable and accrued expenses		46,616	38,069
Security deposits payable		8,844	6,570
Other liabilities and deferred credits		49,547	46,061
Total liabilities		1,395,779	1,415,720
American Assets Trust, Inc. stockholders' equity
Accumulated other comprehensive income		14,591
TOTAL LIABILITIES AND EQUITY		2,198,250	2,259,864
Partners' Capital [Abstract]
Limited partners' capital, 17,177,608 and 17,194,980 units issued and outstanding as of December 31, 2018 and December 31, 2017, respectively		(4,477)
General partner's capital, 47,335,409 and 47,204,588 units issued and outstanding as of December 31, 2018 and December 31, 2017, respectively		792,357
Total capital		802,471	844,144
Limited Partner | American Assets Trust, L.P.
Partners' Capital [Abstract]
Limited partners' capital, 17,177,608 and 17,194,980 units issued and outstanding as of December 31, 2018 and December 31, 2017, respectively			6,135
Total capital	[1]	(4,477)	6,135
General Partner | American Assets Trust, L.P.
Partners' Capital [Abstract]
General partner's capital, 47,335,409 and 47,204,588 units issued and outstanding as of December 31, 2018 and December 31, 2017, respectively			822,259
Total capital	[2]	792,357	822,259
Accumulated Other Comprehensive Income (Loss) | American Assets Trust, L.P.
American Assets Trust, Inc. stockholders' equity
Accumulated other comprehensive income			15,750
Partners' Capital [Abstract]
Total capital		$ 14,591	$ 15,750

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

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