Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES
Net income	$ 40,132	$ 45,637	$ 53,915
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(2,547)	(2,637)	(5,587)
Depreciation and amortization	83,278	71,319	63,392
Amortization of debt issuance costs and debt fair value adjustments	3,058	4,473	4,214
Gain on sale of real estate	0	0	(7,121)
Stock-based compensation expense	4,735	2,414	2,877
Settlement of forward interest rate swap agreement	10,667	0	0
Other noncash interest expense	(1,114)	(231)	(231)
Other, net	901	(769)	879
Changes in operating assets and liabilities
Change in accounts receivable	(1,116)	(2,347)	(1,011)
Change in other assets	(499)	(982)	(243)
Change in accounts payable and accrued expenses	7,632	1,371	(1,081)
Change in security deposits payable	456	158	493
Change in other liabilities and deferred credits	270	2,275	(36)
Net cash provided by operating activities	145,853	120,681	110,460
INVESTING ACTIVITIES
Acquisition of real estate, net	278,141	0	0
Capital expenditures	(47,496)	(59,633)	(134,174)
Proceeds from sale of real estate, net of selling costs	0	0	12,259
Leasing commissions	(4,927)	(3,572)	(4,461)
Net cash used in investing activities	(330,564)	(63,205)	(126,376)
FINANCING ACTIVITIES
Repayment of secured notes payable	(167,139)	(136,974)	(235,980)
Proceeds from unsecured term loan	0	150,000	0
Proceeds from unsecured line of credit	173,000	34,000	65,000
Repayment of unsecured line of credit	193,000	44,000	35,000
Proceeds from issuance of unsecured notes payable	450,000	0	200,000
Debt issuance costs	(2,401)	(2,055)	(2,881)
Proceeds from issuance of common stock, net	29,873	9,640	72,782
Dividends paid to common stock and unitholders	(67,537)	(64,077)	(59,412)
Shares withheld for employee taxes	(882)	(807)	(7,396)
Net cash provided by (used in) financing activities	221,914	(54,273)	(2,887)
Net (decrease) increase in cash and cash equivalents	37,203	3,203	(18,803)
Cash, cash equivalents and restricted cash, beginning of year	54,751	51,548	70,351
Cash, cash equivalents and restricted cash, end of year	91,954	54,751	51,548
Cash and cash equivalents	82,610	44,801	39,925
Restricted cash	9,344	9,950	11,623
American Assets Trust, L.P.
OPERATING ACTIVITIES
Net income	40,132	45,637	53,915
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(2,547)	(2,637)	(5,587)
Depreciation and amortization	83,278	71,319	63,392
Amortization of debt issuance costs and debt fair value adjustments	3,058	4,473	4,214
Gain on sale of real estate	0	0	(7,121)
Stock-based compensation expense	4,735	2,414	2,877
Settlement of forward interest rate swap agreement	10,667	0	0
Other noncash interest expense	(1,114)	(231)	(231)
Other, net	901	(769)	879
Changes in operating assets and liabilities
Change in accounts receivable	(1,116)	(2,347)	(1,011)
Change in other assets	(499)	(982)	(243)
Change in accounts payable and accrued expenses	7,632	1,371	(1,081)
Change in security deposits payable	456	158	493
Change in other liabilities and deferred credits	270	2,275	(36)
Net cash provided by operating activities	145,853	120,681	110,460
INVESTING ACTIVITIES
Acquisition of real estate, net	278,141	0	0
Capital expenditures	(47,496)	(59,633)	(134,174)
Proceeds from sale of real estate, net of selling costs	0	0	12,259
Leasing commissions	(4,927)	(3,572)	(4,461)
Net cash used in investing activities	(330,564)	(63,205)	(126,376)
FINANCING ACTIVITIES
Repayment of secured notes payable	(167,139)	(136,974)	(235,980)
Proceeds from unsecured term loan	0	150,000	0
Proceeds from unsecured line of credit	173,000	34,000	65,000
Repayment of unsecured line of credit	193,000	44,000	35,000
Proceeds from issuance of unsecured notes payable	450,000	0	200,000
Debt issuance costs	(2,401)	(2,055)	(2,881)
Contributions from American Assets Trust, Inc.	29,873	9,640	72,782
Dividends paid to common stock and unitholders	(67,537)	(64,077)	(59,412)
Shares withheld for employee taxes	(882)	(807)	(7,396)
Net cash provided by (used in) financing activities	221,914	(54,273)	(2,887)
Net (decrease) increase in cash and cash equivalents	37,203	3,203	(18,803)
Cash, cash equivalents and restricted cash, beginning of year	54,751	51,548	70,351
Cash, cash equivalents and restricted cash, end of year	91,954	54,751	51,548
Cash and cash equivalents	82,610	44,801	39,925
Restricted cash	$ 9,344	$ 9,950	$ 11,623