Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income	$ 60,188	$ 27,202	$ 40,132
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(6,985)	(1,157)	(2,547)
Depreciation and amortization	96,205	107,093	83,278
Amortization of debt issuance costs and debt fair value adjustments	1,467	1,530	3,058
Gain on sale of real estate	633	0	0
Stock-based compensation expense	4,477	3,039	4,735
Settlement of forward interest rate swap agreement	513	0	10,667
Lease termination income	(4,518)	0	0
Other noncash interest expense	(1,304)	(1,279)	(1,114)
Other, net	6,497	383	901
Changes in operating assets and liabilities
Change in accounts receivable	(1,071)	(336)	(1,116)
Change in other assets	(2,420)	(227)	(499)
Change in accounts payable and accrued expenses	5,956	(3,297)	7,632
Change in security deposits payable	(971)	2,274	456
Change in other liabilities and deferred credits	(3,585)	1,282	270
Net cash provided by operating activities	153,816	136,507	145,853
INVESTING ACTIVITIES
Acquisition of real estate, net	507,780	0	278,141
Capital expenditures	(88,327)	(54,411)	(47,496)
Proceeds from sale of real estate, net of selling costs	8,191	0	0
Leasing commissions	(11,267)	(9,936)	(4,927)
Net cash used in investing activities	(599,183)	(64,347)	(330,564)
FINANCING ACTIVITIES
Repayment of secured notes payable	(20,762)	(97,124)	(167,139)
Proceeds from unsecured line of credit	59,000	84,000	173,000
Repayment of unsecured line of credit	123,000	20,000	193,000
Proceeds from issuance of unsecured notes payable	150,000	0	450,000
Debt issuance costs	(1,103)	(2,727)	(2,401)
Proceeds from issuance of common stock, net	515,354	(236)	29,873
Dividends paid to common stock and unitholders	(80,605)	(70,228)	(67,537)
Shares withheld for employee taxes	(1,338)	(527)	(882)
Net cash provided by (used in) financing activities	497,546	(106,842)	221,914
Net (decrease) increase in cash and cash equivalents	52,179	(34,682)	37,203
Cash, cash equivalents and restricted cash, beginning of year	57,272	91,954	54,751
Cash, cash equivalents and restricted cash, end of year	109,451	57,272	91,954
Cash and cash equivalents	99,303	47,956	82,610
Restricted cash	10,148	9,316	9,344
American Assets Trust, L.P.
OPERATING ACTIVITIES
Net income	60,188	27,202	40,132
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred rent revenue and amortization of lease intangibles	(6,985)	(1,157)	(2,547)
Depreciation and amortization	96,205	107,093	83,278
Amortization of debt issuance costs and debt fair value adjustments	1,467	1,530	3,058
Gain on sale of real estate	633	0	0
Stock-based compensation expense	4,477	3,039	4,735
Settlement of forward interest rate swap agreement	513	0	10,667
Lease termination income	(4,518)	0	0
Other noncash interest expense	(1,304)	(1,279)	(1,114)
Other, net	6,497	383	901
Changes in operating assets and liabilities
Change in accounts receivable	(1,071)	(336)	(1,116)
Change in other assets	(2,420)	(227)	(499)
Change in accounts payable and accrued expenses	5,956	(3,297)	7,632
Change in security deposits payable	(971)	2,274	456
Change in other liabilities and deferred credits	(3,585)	1,282	270
Net cash provided by operating activities	153,816	136,507	145,853
INVESTING ACTIVITIES
Acquisition of real estate, net	507,780	0	278,141
Capital expenditures	(88,327)	(54,411)	(47,496)
Proceeds from sale of real estate, net of selling costs	8,191	0	0
Leasing commissions	(11,267)	(9,936)	(4,927)
Net cash used in investing activities	(599,183)	(64,347)	(330,564)
FINANCING ACTIVITIES
Repayment of secured notes payable	(20,762)	(97,124)	(167,139)
Proceeds from unsecured line of credit	59,000	84,000	173,000
Repayment of unsecured line of credit	123,000	20,000	193,000
Proceeds from issuance of unsecured notes payable	150,000	0	450,000
Debt issuance costs	(1,103)	(2,727)	(2,401)
Contributions from American Assets Trust, Inc.	515,354	(236)	29,873
Dividends paid to common stock and unitholders	(80,605)	(70,228)	(67,537)
Shares withheld for employee taxes	(1,338)	(527)	(882)
Net cash provided by (used in) financing activities	497,546	(106,842)	221,914
Net (decrease) increase in cash and cash equivalents	52,179	(34,682)	37,203
Cash, cash equivalents and restricted cash, beginning of year	57,272	91,954	54,751
Cash, cash equivalents and restricted cash, end of year	109,451	57,272	91,954
Cash and cash equivalents	99,303	47,956	82,610
Restricted cash	$ 10,148	$ 9,316	$ 9,344